:-NRLF 


OF  THE     H         \ 

UNIVERSITY   I 

OF  / 


The    Great    Nebula    in    Andromeda,    from  a  photograph  by 
Professor  G.  W.  Ritchie  of  the  Yerkes  Observatory. 


RADIANT  ENERGY 

AND  ITS  ANALYSIS 

ITS  RELATION  TO  MODERN  ASTROPHYSICS 


BY 

EDGAR    L.  LARKIN 

DIRECTOR  LOWE  OBSERVATORY 
KCHO  MOUNTAIN,  CALIFORNIA 

Fellow  of  the  American  Association    for  the  Advancement  of  Science 

Member  of  the  Astronomical  Society  of  the  Pacific 
Fellow  of  the  Southern  California  Academy  of  Sciences 


ILLUSTRATED 


"  Many  thousands  of  unrecorded  nebula.'  exist  in  the  sky. 
A  conservative  estimate  places  the  number  within  reach  of 
the  Crossley  reflector  at  about  120,000."— /awes  E.  Keelc, . 

"  Darkness  there  was,  and  all  at  first  was  veiled  in  gloom  pro- 
found, an  ocean  without  lig^it."  Ri<;  feda,  loth  Ch.,  Hymn  i2i>. 


.*-—  •  •"        :^5^. 
fV     Oc  THE  \ 

t  V'M'  ) 

/ 

L9O3 

BAUMGARDT    PUBLISHING    COMPANY 
LOS  ANGKLKS,  CALIFORNIA 


COPYRIGHTED  1903, 

BY  BAUMGARDT  PUBLISHING  COMPANY, 
L,os  ANGELES,  CALIFORNIA 


TO 

JOHN   D.  HOOKER 

WHO  IN   THE  MIDST   OF   THE  PRESSING   DUTIES 

OF   A  BUSINESS   CAREER   STILL   FINDS 

TIME   TO   DEVOTE   TO  SCIENCE 

AND   ITS    ADVANCEMENT 

IN     SOUTHERN 

CALIFORNIA 

THIS  BOOK  IS  DEDICATED 


175084 


INTRODUCTORY. 


Upon  coming  to  the  Pacific  Coast,  the  writer  was  engaged 
by  Dent  H.  Robert,  editor  of  the  San  Francisco  Examiner,  to 
contribute  a  series  on  modern  physical  science.  The  subject  se- 
lected was,  "Radiant  Energy  and  Its  Analysis,"  together  with  its 
application  to  astronomy  and  astro-physics — the  latter  being  an 
entirely  new  branch  of  research  into  the  laws  of  nature.  The 
text  as  it  appears  here,  and  also  the  cuts,  appeared  in  the  Ex- 
aminer, from  February  to  August,  1902.  The  writer  re- 
ceived so  many  letters  on  the  subject  matter  of  the  series,  and 
upon  the  discussions  therein  and  questions  involved,  that  it  was 
desired  that  the  whole  should  be  published  in  book  form.  The 
matter  was  considered  by  the  officers,  William  H.  Knight,  Presi- 
dent, and  r>.  R.  Baumgardt,  Secretary,  and  many  of  the  mem- 
bers of  the  Southern  California  Academy  of  Sciences.  No  funds 
were  in  sight,  so  the  Vice-President,  J.  D.  Hooker,  came  to  the 
rescue  and  said  he  would  see  the  book  through  the  press.  For 
this,  he  not  only  has  the  thanks  of  the  writer,  but  of  the  mem- 
bers of  the  Academy  also.  Special  regard  is  gratefully  accorded 


I NT  ROD UCTOR Y 

to  those  two  eminent  women,  the  Misses  Matilda  H.  and  Jennie 
M.  Smith,  of  Allegheny,  Pennsylvania,  for  their  beautiful  present 
of  a  spectt-ograph  and  heliostat.  These  splendid  instruments 
were  made  by  that  accomplished  mechanic,  John  A.  Brashear, 
of  Allegheny,  and  presented  to  the  writer  upon  their  order. 
Here  is  a  case  where  two  wealthy  women  devote  their  time  and 
means  to  the  cause  of  science  and  the  aid  of  research  into  the 
most  inscrutable  laws  of  the  natural  world. 

To  the  Baumgardt  Publishing  Co.  is  due  the  credit  of  a 
perfect  publication,  in  composition,  arrangement  and  high-class 
press  work.  Thanks  are  tendered  to  Mausard,  Collier  &  Co.  of 
Los  Angeles  for  their  fine  production  of  many  of  the  cuts.  In 
many  cases  the  originals  were  very  poor,  some  scarcely  legible. 
The  Lick  Observatory,  Mount  Hamilton,  Calif.,  also  kindly  fur- 
nished the  pictures  of  their  telescope  and  spectrographs. 

Thanks  are  due  to  Professor  E.  E.  Barnard  of  the  Yerkes 
Observatory  for  the  exceptionally  fine  graphs  of  the  Milky  Way 
and  of  the  great  Nebula  in  Andromeda,  as  well  as  of  the  tele- 
scope and  spectrograph  in  that  observatory.  The  graphs  of  the 
solar  prominences  secured  on  the  eclipse  expedition  are  of  great 
beauty  and  perfection.  These  pictures  were  prepared  by  Ferdi- 
nand Ellerman,  the  observatory  photographer. 

Acknowledgements  are  due  to  William  H.  Knight  of  Los 
Angeles  for  reviewing  the  work,  critically  examining  the  whole 
and  noting  imperfections. 

Since  the  beginning  of  the  series,  the  astro-physicists  of  the 
world  have  made  many  more  researches  and  discoveries.  Enough 
material  is  now  on  hand  from  all  these  to  fill  another  volume 


INTRODUCTOR  V 

like  this.  The  scientific  brain  of  the  world  is  in  a  state  of  in- 
tense activity,  the  most  recondite  and  elaborate  studies  are 
under  way — and  knowledge  is  moving  with  ever-increasing  mo- 
mentum. The  most  skillful  detectives  of  nature  are  at  work 
hourly  in  every  possible  way,  striving  to  find  out  what  matter  is, 
and  also  energy.  At  present  both  are  unknown ;  they  may  for- 
ever remain  unknown,  but  if  it  can  be  proven  that  they  are  un- 
knowable, this  at  least  would  afford  a  resting  place  for  wan- 
dering thought,  wandering  along  the  borders  of  infinity. 

EDGAR  L.  LARKIN. 


RADIANT     ENERGY.  i7 


I. 

RADIANT  ENERGY. 

"Our  fathers  resorted  to  Indra  of  old :  they  discovered  the  hidden 
light  and  caused  the  dawn  to  rise." — Rig  Veda.  Muir's  Sanskrit,  Texts 
39-2.  I  48,  14. 

Radiant  here  means  proceeding  from  a  center  in  straight  lines 
in  every  direction.  Energy  is  internal  and  inherent.  Professor 
Barker,  Physics,  page  4,  says :  "Energy  is  defined  as  a  condition 
of  matter  in  virtue  of  which  any  definite  portion  may  effect 
changes  in  any  other  definite  portion."  This  was  written  in  1892, 
and  discoveries  since  confirm  it.  Energy,  then,  is  a  state  of  mat- 
ter, or,  rather,  the  result  of  a  particular  state  or  condition  in  which 
matter  may  be  when  any  observed  phase  of  energy  appears. 

These  two,  matter  and  energy,  or,  possibly  one,  is  the  sum 
total  of  all  that  has  been  found  during  three  centuries  of  incessant 
research  in  all  that  portion  of  the  universe  visible  in  a  forty-inch 
telescope  armed  with  the  most  powerful  spectroscope  ever  made. 

It  is  the  belief  of  the  writer  that  all  this  space  is  saturated 
with  inconceivably  minute  corpuscles,  those  recently  discovered 
by  Professor  J.  J.  Thomson.  These  are  doubtless  either  electricity 
in  its  ultimate  refinement,  or  very  closely  allied  to  it,  or  its  imme- 
diate carriers.  The  smallest  particle  of  hydrogen,  long  time  called 
an  "atom,"  has  been  thought  to  be  the  least  in  mass  of  any  known 
particle  of  matter;  but  the  corpuscles  detected  by  Thomson  have 


'S  RADIANT     ENERGY. 

only  one-thousandth  of  the  mass  of  the  hydrogen  atom.  The 
earth  and  sun,  all  suns  and  dark  bodies  in  space,  all  granular  mat- 
ter move  through  the  primordial  cosmical  mass  of  electrical  cor- 
puscles as  would  a  wire  screen  through  water.  The  wide  spaces 
in  diamond,  glass,  steel,  flint  or  anything  else  allow  these  "bodies 
smaller  than  atoms,"  as  Thomson  calls  them,  to  pass  through. 

From  the  record-breaking  discoveries  of  the  physicists  Curie, 
in  previously  unknown  waves,  it  is  coming  to  be  seen  that  all 
matter  is  radio-active.  All  phases  of  matter,  such  as  radium, 
barium,  uranium,  thorium,  polonium,  vanadium,  cereum,  molyb- 
denum, zinc,  aluminum,  etc.,  emit  obscure  undulations,  and  these 
imprint  radiographs  on  sensitive  photographic  plates. 

Radium  is  so  active  that  its  potential  has  been  measured  and 
with  a  delicate  watt  meter  its  power  has  been  'determined.  Thom- 
son's corpuscles  are  plus  and  minus  in  their  electrical  charges,  the 
positive  carriers  of  electricity  being  comparable  in  size  to  ordi- 
nary atoms  of  gross  matter;  but  the  corpuscles  that  flow  between 
the  atoms  of  all  types  of  matter  are  negative.  The  corpuscles 
emitted  by  radium  are  negative  and  can  be  bent  out  of  their  course 
by  the  plus  pole  of  a  magnet — so  that  active  matter  sends  out  per- 
petually the  same  kind  of  corpuscles  that  fill  all  space.  It  is 
incredible  that  these  radiating  bodies  forever  emit  corpuscles 
without  receiving  them  from  the  primeval  store.  Therefore  radio- 
active masses  are  simply  more  transparent  to  corpuscles  from 
space  than  others,  or  change  their  directions  of  motion. 

The  fact  that  negative  ions  can  be  deflected  by  magnets  is  one 
hidden  deep  in  the  end  of  a  long  corridor  in  nature,  a  passage 
more  inscrutable  than  those  in  the  Pyramid  of  Suphis. 

TRANSMISSION. 

From  the  definition  of  energy  it  is  the  potential  of  the  uni- 
verse. When  matter  is  in  a  phase  allowing  it  to  be  active,  it 
efTects  other  quantities  of  matter  at  a  distance.  The  method  of 


7?  A  D  I  A  N  T      E  N  ERG  Y.  i9 

transfer  is  known  to  be  by  means  of  wave  motion.  Each  impulse 
moves  from  the  emitting  to  the  receiving  mass  on  a  rigorously 
straight  line.  One  continuous  set  of  oscillations  in  this  right  line 
is  called  a  ray.  Each  negative  or  Thomsonian  corpuscle  makes 
a  double  vibration  to  and  fro  like  a  pendulum  straight  across  the 
direction  of  the  ray — i.  e.,  at  right  angles  to  it,  the  corpuscle  moves 
over  and  returns  to  its  original  position  had  before  the  excursion. 
Since  the  corpuscles  are  negative  and  can  be  drawn  out  of  their 
original  straight  path  by  the  action  of  magnetism,  the  entire  wave 
motion  of  the  universe  is  electro-magnetic.  This  is  what  Maxwell 
prophesied  forty  years  ago.  Thomson  fulfilled  the  prophecy. 


Cut  1.     Waves. 


After  one  corpuscle  makes  an  oscillation  across  the  direction 
of  the  ray  and  return  the  next  does  likewise,  and  the  next,  and  so 
on.  After  the  first  corpuscle  makes  swing,  another  distant  from 
it  186,000  miles  in  the  same  straight  line  will  also  make  a  vibra- 
tion at  the  end  of  the  first  second  of  time. 

In  figure  I,  cut  I,  the  distances  of  the  sides  of  the  waves 
from  the  central  straight  line  of  the  ray  is  amplitude,  or  the 
distance  each  corpuscle  swings  on  either  side.  Since  each  wave 
must  be  distant  from  its  source,  186,000  miles  at  the  end  of  one 
second,  it  follows  that  variations  in  the  lengths  of  the  waves 
occur,  those  having  the  greatest  amplitude  being  the  longest— 


20 


RADIANT     ENERGY. 


that  is,  a  less  number  will  be  contained  in  a  centimeter,  as  shown 
in  diagram.  Really  there  is  no  such  thing  as  a  ray ;  the  straight 
line  along  the  middle  of  each  set  of  waves  was  simply  drawn  to 
show  direction  of  the  waves  and  to  show  the  amplitudes  on  either 
side.  A  cannon  ball  carries  matter  and  energy  while  corpuscular 
disturbances  transmit  energy  from  an  active  phase  of  matter  to  a 
passive  or  receiving,  non-vibrating  phase.  If  one  inch  contains 
from  34,000  to  61,000  electro-magnetic  undulations,  their  effect 
on  human  sensation  is  called 

LIGHT. 

With  34,000  to  the  inch,  everybody  agrees  in  saying  they  see 
red;  if  61,000,  violet,  with  an  indefinite  number  of  colors  between. 


Cut  2.     Dark  Room.     L,ight  Entering  from  Sun. 

For  physicists  to  examine  the  properties  of  light  it  must  be  first 
bent  out  of  its  course.  The  best  place  to  work  is  in  a  dark  room, 
where  all  light  is  excluded  except  one  pencil  of  waves  admitted 
through  a  minute  opening. 

In  cut  2,  a  band  of  light  is  shown  coming  from  the  mirror 
of  a  heliostat.  The  bundle  of  waves  crosses  the  room  and  makes 
a  bright  image  of  the  aperture  on  a  white  screen.  The  heliostat 
mirror  is  turned  by  a  clock  one  way  as  fast  as  the  earth  turns 
the  other,  so  the  light  is  in  the  room  from  sunrise  to  sunset.  That 
is,  the  sun  seems  to  be  at  rest  in  space,  hence  the  name  of  "sun 
standstill." 


RADIANT      ENERGY. 


21 


TURNING  WAVES  OUT  OF  THEIR  COURSE. 

In  figure  3,  of  any  transparent  substance  is  placed  in  the  beam 
of  waves  at  right  angles  to  it  as  at  A,  no  effect  is  produced ;  the 
white  spot  is  still  seen  on  the  screen.  But  incline  the  transmit- 
ting body  as  at  B  and  a  marvelous  thing  is  seen — the  bright  spot 
moves  aside.  This  has  elicited  the  admiration  of  every  physicist 
from  Newton  to  the  present.  It  is  a  fundamental  rock-hewn 
foundation  stone  of  nature.  Without  it  no  telescope,  microscope, 
camera  or  spectroscope  or  any  lens  whatever  could  be  made — 
and  men  would  now  be  in  complete  ignorance  of  the  universe 
round  about.  The  waves  at  I  are  incident,  at  R  refracted,  and 


KCO/V( 


Cut  3.     Refraction  of  L,ight  by  Inclined  Medium. 

at  E  emergent,  but  the  entering  and  leaving  bands  are  parallel ; 
the  emergent  line  of  waves  being  bodily  shifted  aside,  their  motion 
coming  to  an  end  in  the  bright  spot  C,  having  moved  from  D. 
This  phenomenon  is  called  refraction — to  bend  or  break.  The 
diameter  of  the  bright  dot  on  the  screen,  however,  is  the  same  at 
C  and  D.  The  light  yet  is  not  in  a  condition  to  analyze. 

Instead  of  putting  a  flat  medium  with  parallel  lines  in  the 
waves  as  at  B,  insert  one  with  inclined  sides  as  at  P,  figure  4. 
The  emergent  band  instantly  widens,  the  bright  spot  vanishes,  a 
broad  and  long  band  of  light  containing  every  color  from  red  to 
violet  flashes  on  the  screen.  It  is  the 


22 


RADIANT     ENERGY. 


SOLAR  SPECTRUM, 

one  of  the  most  impressive  visions  ever  seen  by  the  eye  of 
man,  and  is  now  known  to  be  one  of  the  most  valuable  of  human 
possessions.  This  separation  by  inclined  surfaces  of  a  transmit- 
ting medium  is  termed  dispersion,  or  separation  of  all  the  differ- 
ent wave  lengths,  the  shortest  waves — violet  sensation — being  bent 
aside,  dispersed  or  removed  to  the  greatest  distance  from  the 
original  straight  line — the  incident  pencil — while  long  waves — 
red — are  turned  aside  the  least,  with  every  other  light  wave  be- 
tween, the  phenomenon  being  classed  under  the  head  of  different 
refrangibility,  or  of  varying  rates  of  refraction,  for  dispersion 


Cut  4.     Dispersion  of  lyight  by  Medium  with  its  Inclined  Sides — a  Prism. 

is  not  a  physical  fact' in  nature  by  itself,  it  being  merely  refraction. 
Since  1859,  when  Kirchhoff  laid  the  foundation  of  modern  spec- 
troscopy,  many  of  the  most  refined  intellects  of  the  world  have 
studied  incessantly  the  properties  of  this  glorious  band  of  colors. 
Indeed,  only  one  line  of  research  ever  undertaken  by  man  has 
exceeded  it  in  intensity  of  thought — the  calculus.  Today  there 
stands  a  majestic  science,  profound  in  its  conclusions,  far-reach- 
ing in  its  determinations,  approaching  sublimity  in  its  deductions 
regarding  the  composition,  construction  and  potential  of  the  uni- 
verse. 

It  is  spectrum  analysis.    Let  its  study  be  continued, 


R  A  D  I  ANT     E  N  B  R  G  Y.  23 


II. 

SPECTRUM  ANALYSIS. 

By  the  radiant  light  of  the  universal  magnetic  ocean,  electric  waves 
bind  the  cosmos  together." — Veil  of  Isis,  Vol.  i,  p.  282. 

The  reason  why  the  colored  band — the  spectrum — is  so  valu- 
able is  that  in  it  the  waves  are  separated.  Each  length  of  oscilla- 
tion is  by  itself  and  in  a  state  suitable  for  measuring-.  Also  the 
properties  of  each  wave  can  be  studied  in  their  reactions  on  each 
other,  and  what  is  of  great  importance,  the  action  of  each  kind 
of  vibration  on  gross  matter.  Our  lives  and  existence  on  earth 
depend  entirely  on  these  waves,  also  the  only  knowledge  so  far 
secured  regarding  the  universe  and  the  earth's  place  and  man's 
place  therein  has  come  from  three  centuries  of  study  of  these  tiny 
undulations.  Waves  therefore  constitute  a  fundamental  fact  in 
nature,  and  should  be  studied  bv  all  who  have  the  slightest  regard 

<*>  o 

for  nature  and  her  works.     Every  operation  in  the  natural  world 
round  about  is  carried  on  by  the  most  rigid  and  inexorable  law. 

LAW   I. 

All  solids,  liquids  and  gases,  under  great  pressure,  project 
continuous  spectra  when  incandescent. 

This  is  one  cornerstone  in  that  majestic  edifice,  spectrum 
analysis. 


24  R  A.  DI  ANT     U  N  ERG  Y. 

BUILDING  UP  A   SPECTRUM. 

In  cut  4,  stop  the  clock  of  the  heliostat  and  place  a  hot 
iron  in  front  of  the  mirror,  between  it  and  the  prism.  Hold 
the  hand  near  the  iron,  heat  is  the  sensation  imparted  by  the  black 
mass.  It  is  at  once  known  that  the  iron  is  emitting  waves.  They 
are  invisible,  being  too  long  and  too  slow  in  rate  of  vibration  to 
act  on  the  retinal  nerves.  Heat  the  iron  hotter ;  watch  closely  and 
dull  red  will  appear. 

Increase  the  heat ;  all  shades  of  red  will  develop,  from  dull 
to  bright.  Millions  of  different  waves  differing  in  lengths  and 
rates  will  be  seen.  Reflect  the  rays  through  the  prism,  look  on 


F1C.I.    ONLY  RED    RATES  'APPEAR. 


VIOLE.TI  its&i&o  BLUE  c^m  YELLOW  ORANGE  RU 

FIG-A  ALL   8ATE.S-     SPUTRUM    CONTINUOUS 


FIC.-3    SPtCTRUM    WITH     7    RATtS 

Cut  5.     Three  Spectra. 

the  white  screen  on  the  other  side,  and  figure  i,  cut  5,  will  flash 
out.  A  band  of  red  light  will  be  seen  extending  from  deep  to 
bright  red.  This  is  because  it  emits  only  red  rays ;  not  being- 
hot  enough — i.  e.,  its  internal  particles  do  not  oscillate  fast  enough 
to  send  forth  any  other  lengths  of  waves.  It  is  said  that  the 
metal  is  "red-hot." 

For  deep  dark  red,  one  inch  contains  33,000  waves,  and  for 
deep  low  musical  notes  in  a  piano,  vibrating  32  times  per  second, 
the  wave  length  is  thirty-five  feet.  So  one  deep  bass  wave  from 
an  organ  is  13,860,000  times  longer  than  a  bass  wave  of  light 
called  red. 


R  A  D  I  A  N  T     B  N  H  R  G  Y.  25 

Heat  the  iron  still  hotter,  it  begins  to  lose  its  red  color  and  be- 
comes white.  Look  at  the  screen,  then  figure  2,  cut  5,  will  be  seen. 
It  is  a  continuous  spectrum,  continuous  because  all  wave  lengths, 
all  rates,  are  present.  And  these  rates  of  vibrations  are  colors. 
For  color  in  light  is  pitch  in  sound.  Still  increase  the  heat  of  the 
iron,  it  becomes  a  liquid,  but  the  liquid  is  still  white ;  it  emits  every 
possible  rate,  and  the  band  of  color  is  still  complete  but  brighter 
than  before,  because  the  liquid  iron  is  whiter  than  solid.  But, 
during  all  this  time,  great  events  are  happening  outside  the 
visible  spectrum  beyond  the  violet,  in  that  mysterious  region 
called  the  ultra-violet,  now  being  explored  with  feverish  anxiety 
by  physicists  to  find  more  invisible  rates  in  waves,  and 
they  are  being  discovered  almost  daily.  The  oscillating  particles 
of  iron  set  vibrating  by  the  heat,  beat  so  rapidly  that  the  eye 
cannot  follow  the  short  waves  sent  out,  for  the  invariable  product 
of  swings  of  particles  is  waves  set  up  inside  and  surrounding 
every  particle  of  matter  in  nature.  For  the  shortest  violet  wave 
just  within  range  of  acute  eyes,  before  final  extinction  in  the 
invisible  ultra-violet,  has  length  such  that  61,000  are  within  one 
inch.  And  the  highest  musical  sound  caused  by  a  piano  wire 
oscillating  4,000  times  per  second  is  conveyed  by  a  wave  three 
and  one-third  inches  long. 

Some  can  hear  sound  when  the  wave  length  is  four-tenths 
of  an  inch  in  length,  but  it  is  not  music — merely  a  very  shrill 
sound.  Thus,  all  sound  waves  are  exceedingly  long  compared 
with  light  waves. 

HARMONIES    IN    NATURE. 

A  continuous  spectrum  is,  therefore,  comparable  to  the  key- 
board of  an  organ,  with  every  key  open,  the  bellows  being  in 
constant  action,  the  bellows  corresponding  to  the  continuous 
shining  of  the  sun,  or  other  source  of  white  light.  For  the  organ 
issues  every  musical  note,  and  the  continuous  spectrum  is  made 


26  R  A  D  J  A  N  T     B  N  B  R  G  Y. 

up  of  every  harmonic  (musical)  light — else  it  would  not  have 
been  emitted  by  a  white  source.  And  this  is  why  the  musical  is 
called  the  color  or  chromatic  scale.  Harmonics  lie  deep  in  nature, 
and  their  study  has  developed  into  a  vast  complex  and  mathe- 
matical science.  But  before  the  dark  mass  of  iron  became  en- 
dowed with  the  swings  or  excursions  to  and  fro  of  its  particles 
rapid  enough  to  emit  dull  red,  it  was  at  work  in  an  invisible 
region  beyond  the  red  in  issuing  long,  slow,  heat  waves,  all  too 
long  and  too  slow  to  have  effect  on  the  retinal  nerves. 

But  that  marvel,  the  bolometer,  contains  a  platinum  nerve  of 
exceeding  delicacy  and  this  detects  the  long  waves  far  and  away 
beyond  the  limits  of  the  slowest  red.  The  fast  short  waves  be- 
yond the  most  rapid  violet  are  detected  by  the  fluoroscope  by 
slowing  down  rates  and  changing  lengths,  while  the  gelatine- 
bromide  plates  clutch  the  waves  in  space  by  the  million  and  holds 
their  energy  fast  in  particles  of  silver.  And  the  rapid  and  slow 
invisible  portions  of  the  spectrum  are  at  present  explored  to  about 
sixteen  times  the  length  of  the  visible,  thirteen  times  in  the  ultra- 
violet and  three  times  in  the  infra-red.  So  human  nerves  are 
not  as  sensitive  as  might  be  supposed,  for  platinum  and  silver 
are  both  more  sensitive. 

Now  by  a  complex  process,  heat  the  liquid  iron  hotter  than 
ever,  turn  it  to  gas  and  confine  it  if  possible  like  vapor  of  water 
in  a  boiler,  and  look  again  upon  its  spectrum  projected  by  prism 
on  screen,  behold !  it  is  continuous  still,  for  white  hot  gas  emits 
every  color,  or  rather  every  rate  as  well  as  white  hot  liquids  and 
solids.  This  is  as  might  be  expected,  for  the  source  of  everv 
color  is  white.  This,  therefore,  is  a  repetition  of  Law  I.  Now, 
after  the  terrific  heat  is  in  full  activity,  after  the  iron  panicles 
have  been  by  it  endowed  with  repulsion  sufficient  to  tear  them 
apart,  forming  a  true  gas,  then  release  the  pressure.  At  once 
the  iron  particles  fly  to  immense  distances  apart — compared  with 
their  diameters,  and  swing  to  and  fro  with  inconceivable  rates, 


RADIANT     ENERGY.  27 

in  paths  termed  their  own  free  paths  of  oscillation.  But  when 
all  pressure  is  removed,  so  that  the  gas  can  expand  and  have 
plenty  of  room  for  its  particles  to  make  their  own  unconfined 
vibration,  a  marvelous  thing  happens ;  an  action  occurs  that  rilled 
the  minds  of  all  physicists  with  admiration,  wrought  mighty 
changes  in  human  concept  of  the  structure  of  nature,  enlarged 
the  shoreless  sea  of  knowledge,  and  inspired  all  who  studied  these 
things  with  enlarged  ideas  of  the  laws  and  magnitude  of  the 
sidereal  universe.  At  the  instant  in  which  the  particles  of  iron 
or  any  other  phase  of  matter  are  allowed  to  vibrate  at  their  own 
rate  a  new  and  mighty  law  takes  effect. 

LAW   II. 

All  phases  of  matter,  when  vibrating  at  their  own  rate,  pro- 
ject discontinuous  or  bright  line  spectra,  no  two  sets  of  lines  being 
alike. 

This  is  another  cornerstone  upon  which  stands  the  temple  of 
nature.  When  the  iron  gas  is  vibrating  in  fervent  heat  the  appear- 
ance on  the  screen  is  shown  in  figure  3,  cut  5,  where  all  continu- 
ity in  the  spectrum  has  vanished,  a  series  of  bright  lines  alone 
remains.  All  the  rest  of  the  band  is  now  dark,  no  light  wave  ap- 
pears save  those  making  up  the  bright  lines.  And  each  phase  of 
matter  known  as  iron,  zinc,  tin,  palladium,  hydrogen,  aluminum, 
thorium,  strontium,  thaliium  or  any  other,  projects  an  entirely 
different  set  of  lines  from  all  the  others.  Each  series  falls  in  the 
1  same  measured  place  in  the  spectrum. 

These  lines  are  the  most  valuable  element  of  knowledge  and 
their  discovery  and  method  of  producing  them  was  one  of  the 
most  remarkable  achievements  of  man.  They  make  up  the  alpha- 
bet of  the  universe,  and  spell  out  messages  from  our  own  and 
other  suns,  and  can  be  read  by  an  expert  as  well  as  the  Morse 
dots  and  dashes  in  the  telegraphic  code.  So  now  the  current  life 
events  of  the  sidereal  hosts  in  space  are  being  read  daily  like  a 


28  RADIANT     ENERGY. 

newspaper,  and  not  only  read  but  recorded  for  future  genera- 
tions of  men  by  that  other  marvel  the  spectro-camera. 

The  long  dark  band  to  the  left  of  the  red  in  figure  I,  cut  5, 
need  not  have  been  drawn ;  its  place  is  to  show  where  the  continu- 
ous belt  of  colors  would  have  been  had  the  light  source  been  white, 
as  in  figure  2.  The  bright  lines  in  figure  3,  said  to  represent  the 
iron  spectrum,  is  tentative,  for  iron  casts  about  480  lines.  So 
far  no  instruments  have  been  mentioned  save  a  hole  in  a  shutter, 
dark  room,  prism  and  screen.  The  spectroscope  itself  must  now 
be  taken  apart,  each  piece  photographed  and  presented  for  study. 


RADIANT     ENERGY. 


III. 
THE  SPECTROSCOPE. 

"Arise !  the  breath  of  our  life  has  come !  The  darkness  has  fled. 
Light  advances — pathway  of  the  sun." — Rig  Veda,  1-113.  Muir's  Transla- 
tion. 

Since  the  corpuscles  of  every  phase  of  matter  when  oscil- 
lating at  their  own  rate  traverse  without  hindrance  their  own 
free  paths,  in  which  case  they  must  be  separated  (exist  in  a  gase- 
ous form),  set  up  disturbances  which  are  known  as  light,  and 
project  bright  lines  in  their  spectra,  complex  instruments  must  be 
had  to  analyze  these  emanations.  The  mechanism  is  called  the 
spectroscope — to  view  the  spectrum.  In  the  beginning  of  this 
comprehensive  study,  the  spectroscope  was  a  simple  instrument, 
but  now  after  half  a  century  of  added  improvement,  has  become 
one  of  the  most  intricate  and  delicate  known  to  science.  Indeed 
it  must  be,  since  its  work  is  to  tell  what  the  universe  is  made  of. 

In  cut  6,  some  of  the  complex  spectroscopic  apparatus  in 
the  Lowe  Observatory  is  on  display.  The  instrument  to  the 
right  marked  i,  2,  3,  is  the  heliostat  (sun  stand  still).  It  is 
outside  the  observatory  in  full  sunshine ;  ( i )  is  the  clock  which 
turns  the  axis  (2)  and  the  large  mirror  (3)  in  a  direction  oppo- 
site to  the  direction  of  rotation  of  the  earth.  The  sun  shines  on 
the  mirror  (3)  and  this  throws  a  broad  band  of  light  from  the 
sun  into  the  laboratory  through  an  open  window.  The  beam  of 


jo  RADIANT     ENERGY. 

light  remains  in  one  position  in  the  room  all  day  if  required, 
the  effect  being  as  though  the  sun  remained  stationary.  The 
axis  (2)  must  be  parallel  to  the  axis  of  the  earth,  and  exactly 
in  the  meridian,  else  the  pencil  of  light  would  wabble  around 
the  central  line.  To  make  the  axis  of  the  heliostat  parallel  to 
that  of  the  earth,  it  must  be  elevated  above  the  horizon  as  many 
degrees  as  the  heliostat  is  removed  from  the  equator  of  the 
earth — that  is,  the  elevation  must  equal  the  latitude.  It  therefore 
points  to  the  pole  of  the  heavens.  This  heliostat  was  a  gift  from 
those  eminent  ladies,  the  Misses  Jennie  M.  and  Matilda  H.  Smith, 


Cut  (').     Spectroscopic  Instruments  in  Lowe  Observatory. 


of  Allegheny,  Pa.  They  devote  their  lives  to  the  encouragement 
of  science.  Without  this  heliostat  the  complex  spectroscope 
would  remain  idle  and  useless  in  the  laboratory. 

The  ray  of  light  passes  into  the  narrow  slit  of  the  spectro- 
scope (5).  This  is  an  opening  between  accurate  metallic  jaws, 
whose  width  is  variable.  Thus  when  it  is  desired  to  see  the 
Fraunhofer  lines  in  the  solar  spectrum,  the  opening  is  narrowed 
to  the  5ooth  part  of  an  inch,  or  even  less.  The  light  emerging 
from  the  slit  is  three-fourths  of  an  inch  high,  for  the  slit  in  sun 
work  is  vertical,  and  the  i-5ooth  of  an  inch  wide.  It  passes 
through  the  collimator  (tube  6)  and  falls  on  a  convex  lens  behind 


RADIANT     ENERGY.  3j 

8,  and  not  shown  in  the  cut.  This  lens  casts  an  exact  image  of 
the  slit  upon  the  diffraction  grating  (7).  This  grating  is  an 
absolutely  flat  piece  of  polished  speculum  metal.  It  has  been 
ruled  with  an  exceedingly  small  diamond  point,  with  lines  14,438 
to  one  inch.  The  space  shown  white  in  7  is  the  ruled  surface 
and  is  i%  by  i«>£  inches,  and  therefore  contains  27,073  lines, 
grooves  cut  in  the  metal,  and  as  many  elevations  of  metal  be- 
tween. These  elevations  and  depressions  cause  incident  light  to 
leave  the  grating  by  reflection  in  odd  multiples  of  half  wave- 
lengths ;  that  is,  when  the  light  is  reflected  away  from  the  ruled 
surface  it  is  in  a  state  of  interference,  the  waves  are  not  in  uni- 
son, crests  and  hollows,  and  crests  and  crests,  interfere,  and 
when  white  light  makes  interference  darkness  or  colors  occur. 

In  the  diffraction  grating  no  darkness  appears,  but  a  glorious 
band  of  colors  is  always  seen  when  sunlight  is  coming  in  at  the 
slit.  It  is  the  most  beautiful  vision  that  the  eye  of  man  has 
looked  upon.  It  is  none  other  than  the  solor  spectrum.  Diffract 
means  to  break ;  the  white  light  is  broken  up  into  an  infinite  num- 
ber of  different  rates  of  vibration — that  is,  colors.  And  color  in 
light  is  comparable  to  pitch  in  sound.  But  when  waves  of  light 
beat  at  their  own  rate,  without  obstruction  from  others,  they  not 
only  appear  under  different  colors,  but  each  tint  takes  on  its  own 
direction,  no  two  colors  being  seen  coming  from  the  same  direc- 
tion. 

Hence  the  thin  slit  one  five-hundredth  of  an  inch  wide, 
since  it  contains  every  rate,  is  widened  into  a  long  narrow  band 
three-fourths  of  an  inch  high,  filled  with  every  color. 

The  band  leaves  the  grating  by  reflection  and  falls  on  the 
convex  lens  (8),  in  the  grating  end  of  the  telescope,  (8,  9).  At 
9  is  another  lens  called  an  eyepiece,  not  shown  in  cut  6,  since 
it  is  now  in  the  hands  of  Brashear,  Allegheny,  Pa.,  to  be  fitted  into 
a  new  spectograph  now  building.  Lens  8  forms  a  brilliant  image 
of  the  band  or  spectrum  on  lens  9,  and  to  an  eye  placed  at  9 


32 

there  is  revealed  a  magnified  band  of  innumerable  colors,  long, 
brilliant  and  marvelous  in  what  it  means. 

But  of  inconceivably  more  importance  than  beauty  or  color, 
the  Fraunhofer  lines  stand  out  in  their  majesty.  There  are  more' 
than  8,000  black  lines,  crossing-  the  spectrum  at  right  angles. 
Some  are  thin  as  a  spider  web,  and  others  from  ten  to  a  thousand 
times  wider.  They  appear  in  all  parts  of  the  spectrum,  from  the 
longest  red  to  the  shortest  violet  undulation.  Their  discovery 
and  translation  is  the  chief  event  that  has  occurred  on  the  earth 
within  the  period  of  written  history. 

About  A.  D.  1600  Kepler  placed  a  prism  in  a  beam  of  sun- 
light and  saw  a  solar  spectrum — the  first  recorded  in  the  annals 
of  science.  A  century  later  Newton  admitted  light  through  a 
round  hole  in  a  shutter  into  a  dark  room,  placed  a  prism  in  the 
beam  and  obtained  a  clearer  band  than  Kepler's.  At  the  end 
of  another  century,  in  1802,  Wollaston  did  what  Newton  per- 
formed, only  he  admitted  the  light  through  a  narrow  slit,  and  his 
was  the  first  mortal  eye  to  see  the  spectrum  crossed  by  a  few 
black  lines.  Twelve  years  later,  Fraunhofer  let  in  light  through 
a  slit,  as  did  Wollaston,  but  happened  to  look  at  the  spectrum 
with  a  small  telescope — an  act  that  changed  the  course  of  science 
for  all  time  and  gave  rise  to  the  chief  study  that  ever  actuated 
the  human  brain — spectrum  analysis. 


RADIAN  T     EN  ER  G  V. 


IV. 


FRAUNHOFER'S  SPECTRUM;. 

"The  bright  one,  whose  powers  are  unequaled.  The  oracle,  the  high 
ruler,  the  southern  sun." — Inscription  on  obelisk  in  Palace  of  Nimrud. 
Primeval  Assyrian,  (Cuneiform)  Talbot's  Trans. 

Fraunhofer,  with  the  little  telescope,  discovered  hundreds  of 
fine,  black  lines  crossing  the  spectrum  of  the  sun  at  right  angles 
to  its  length.  In  cut  7  is  shown  his  original  and  now  historic 
spectrum  of  the  sun,  in  which  he  mapped  576  black  lines. 


Cut  1.    Fraunhofer's  Original  Spectrum. 

Universal  interest  was  at  once  awakened ;  and  it  is  a  fact 
deep  in  psychology  that  the  leading  minds  in  Europe  began 
intense  study  and  labored  on  the  spectrum  from  1814  to  1859,  as 
if  impelled  by  resistless  desire  to  find  the  cause  of  the  mysterious 
lines.  All  realized  that  a  magnificent  law  of  nature  was  con- 
cealed in  the  spectral  bands,  but  none  could  read  the  hand-writing. 


34  RAD  I  A  N  T     E  N  ERG  Y. 

Neither  Herschel,  Young,  Bunsen,  Brewster  and  hundreds  of 
others,  nor  indeed  Fraunhofer,  could  approach  solution  of  the 
cipher  dispatch  from  the  sun.  PAor  forty-five  years  a  most  ex- 
citing search  was  made — one  of  the  most  remarkable  in  the  his- 
tory of  man — in  quest  of  a  mighty  law.  Finally  Kirchhoff  stood 
up,  in  1859,  and  announced  to  a  waiting  world  the  key  that  would 
translate  the  alphabet  of  nature — the  strange  glyphs  in  which  she 
had  for  ages  striven  to  open  up  communication  with  human 
beings. 

Kirchhoff  unlocked  the  gate  of  a  labyrinth  more  inscrutable 
than  that  of  the  Egyptians ;  the  great  doors  swung  on  their  rusty 
hinges,  hundreds  of  barriers  vanished  as  if  by  magic,  and 
he  peered  into  the  long  dark  corridors,  hermetically  sealed,  until 
he  found  the  key. 

The  discovery  of  the  origin  of  the  Fraunhofer  lines  is  equal 
in  importance  to  that  of  the  law  of  gravity,  for  the  law  of  gravi- 
tation "weighs"  the  universe,  and  the  law  of  Kirchhoff  tells  what 
it  is  made  of. 

BUILDING  UP  A  SPECTROSCOPE. 

In  the  cut  published  in  the  third  paper  all  parts  are  shown 
assembled  into  a  complete  instrument.  Each  part  must  be  exam- 
ined separately  to  gain  an  idea  of  this  most  powerful  weapon  in 
the  hands  of  man  for  his  ultimate  conquest  of  nature. 

In  cut  8,  figure  5,  is  shown  the  slit  of  a  modern  spectroscope 
as  made  by  Brashear.  It  is  unscrewed  from  the  end  of  the  col- 
limator  tube.  In  the  cut  the  slit  is  opened  hundreds  of  times 
wider  than  when  in  use,  so  that  it  may  be  seen.  The  light  direct 
from  the  sun  is  sent  by  the  revolving  mirror  of  the  heliostat  (cut 
6)  into  the  narrow  opening.  When  making  an  examination  of 
an  exquisite  Fraunhofer  line,  whose  thickness  is  comparable 
with  that  of  a  spider  web,  the  distance  between  the  jaws  ranges 
from  the  one-five-hundredth  to  the  one-thousandth  part  of  an  inch, 
invisible  almost  to  the  unaided  eye.  But  the  powerful  light  of  the 


RADIANT     ENERGY. 


35 


Cut  8.      Fig.  2,  3,  Electric  Lantern  for  Micrometer  Illumination;  Fig.  5,  Slit  of  Spectro- 
scope ;  Fig.  8,  Collimator  Lens  ;  Fig.  16,  Searchlight  Carbon— 3,1)00,000  Candle 
power ;    Fig.  17,  Two  ordinary  City  Arc  Light  Carbons. 

sun  finds  a  way  through  it  and  falls  on  the  convex  lens  (figure 
8)  in  cut  8,  which  was  detached  from  the  opposite  end  of  the 
collimating  tube. 

The  work  of  this  lens  is  to  project  an  image  of  the  slit  upon 
the  diffraction  grating.  The  slit  is  in  what  is  called  the  prin- 
cipal focus  of  the  lens.  When  any  object  is  in  this  point,  rays 
from  it  emerge  parallel  from  the  lens,  the  effect  being  the  same 
as  though  the  object  (the  slit  in  this  case)  were  at  an  infinite 
distance. 

In  the  Lowe  spectroscope  the  slit  is  five-eighths  of  an  inch 
high  and  of  any  width  desired.  The  jaws  of  the  slit  are  moved 
toward  or  away  from  each  other  by  screws,  and  the  edges  are  as 
straight  as  can  be  made  by  human  hands.  If  not,  the  lines  in 
the  spectrum  would  be  distorted  so  they  could  not  be  measured 
with  the  micrometer.  The  slit,  therefore,  is  a  very  important 
part  of  the  spectroscope  and  corresponds  to  the  narrow  aperture 


36  R  A  D  I  A  N  T     E  N  E  7?  G  Y. 

in  the  shutter  of  a  darkened  window,  employed  by  the  early 
physicists  in  their  gropings  after  a  secret  of  nature,  only  found 
at  the  end  of  250  years  incessant  study. 

The  collimator  is  simply  a  metal  tube  fourteen  inches  long, 
with  slit  at  one  end  and  projecting  lens  at  the  other,  the  sole 
use  of  the  combine  being  to  cast  an  accurate  and  brilliantly 
lighted  image  of  the  slit  upon  the  excessively  fine  rulings  of  the 
grating.  This  bright  image  is  not  magnified — it  is  still  five 
eighths  of  an  inch  high  and  of  the  same  width  as  the  opening  be- 
tween the  jaws. 

PHASES  OF  MATTER  AND  THEIR  ANALYSIS. 

So  far,  these  notes  have  arrived  at  the  cardinal  fact  in  nature 
that  the  solar  spectrum  is  crossed  by  thousands  of  black  lines, 
scattered  here  and  there  in  the  midst  of  gorgeous  colors.  A 
devious  course  was  traversed  by  the  human  mind  before  they 
could  be  translated.  For  lines  cast  in  the  spectra  of  every  phase 
of  matter  known,  are  bright,  highly  colored  and  not  black. 

Before  attacking  the  mighty  problem  of  black  lines  in  the 
spectrum  of  the  sun,  the  bright  lines  must  be  understood. 

If  you  hand  anything  to  a  chemist  for  analysis,  he  will  prob- 
ably dissolve  it  either  in  acid,  water  or  other  solvent,  and  subject 
the  mass  to  the  action  of  reagents.  But  the  spectroscopist  at 
once  subjects  the  substance  to  terrific  heat,  passes  the  light  from 
the  resulting  incandescent  gas  through  the  slit  and  collimating 
lens  and  allows  it  to  fall  on  the  grating. 

Each  phase  of  matter  when  corpuscles  are  torn  apart  and 
separated  far  enough  to  allow  them  to  oscillate,  will  vibrate  at 
its  own  definite  rate.  Each  oscillation  of  a  corpuscle  will  cause 
another  to  swing,  and  another,  the  motion  being  a  wave  move- 
ment. But  each  wave  strikes  its  own  place  in  the  spectrum,  and 
sets  of  similar  waves  form  the  bright  spectrum  lines,  due  entirely 
to  wave  lengths  and  rates  of  oscillation.  The  best  way  to  make 


RADIANT     EN  ERG  Y.  37 

corpuscles  of  metals  swing*  at  their  own  rate  is  to  force  them 
apart  by  the  intense  heat  of  the  electric  arc. 

Figure  16,  cut  8,  is  the  positive  carbon  just  as  it  was  taken 
out  of  the  circuit  short!}''  after  having  been  used  in  the  3,000,000 
candle  power  searchlight  on  Echo  Mountain.  The  crater  is  shown 
scooped  out  deep  into  the  soft  core  of  the  carbon.  In  use  the 
negative  carbon  is  above  this,  separated  by  an  air  space,  through 
which  the  electric  arc  plays  with  its  appalling  force  and  heat. 
Place  the  carbon  points  a  few  inches  from  the  slit,  put  a  chunk 
of  metal  or  metallic  salt  or  compound,  flint,  silicious  compounds, 
rubies,  diamond  or  any  refractory  substance  whatever  into  the 
crater  and  turn  on  the  current  of  electricity.  At  once  the  metal 
or  anything  else  is  turned  white  hot,  and  then  to  a  still  hotter  gas, 
which  fills  all  the  space  between  the  carbon  point  above  and 
crater  below.  But,  at  the  instant  when  the  gas  becomes  hotter 
than  white,  that  is,  when  each  corpuscle  is  torn  away  from  all 
the  others,  each  vibrates  at  its  own  rate,  and  a  set  of  brilliant 
lines  is  seen  on  the  grating,  no  two  sets  being  alike. 

Each  set  is  one  letter  in  nature's  alphabet.  Their  positions 
are  measured  with  accuracy,  and  waves  sent  from  iron,  titanium, 
helium,  or  any  other  phase  always  fall  in  their  own  invariable 
places.  This  is  the  basis  of  spectrum  analysis. 

In  cut  8,  17  is  an  ordinary  city  arc  light  carbon,  with  another 
leaning  against  it  with  wires  attached.  And  these  as  well  as 
still  smaller  are  used  in  spectroscopy,  they  having  craters  large 
and  hot  enough  to  vaporize  metals.  Under  the  figure  5,  half 
covering  the  slit  is  a  total  reflection  prism,  and  light  falling  on 
its  base  is  reflected  by  the  hypotenuse  into  the  slit.  Thus  two 
sets  of  lines  from  two  metals,  or  from  one  metal  and  the  sun 
can  be  projected  on  the  grating  ready  for  analysis  and  comparison. 
The  tube  2-3  is  an  electric  lantern  to  illuminate  the  spider  webs 
in  the  spectro-micrometer,  and  will  be  explained  when  that  in- 
strument is  presented. 


RADIANT     HN  HRGY. 


V. 


"When  thou  seest  the  holy  and  sacred  fire  devoid  of  form,  burning 
and  flying  everywhere  into  the  depths  of  the  universe,  listen  to  the  voice 
of  fire." — Plethon,  Iranic  Literature. 

In  cut  9  a  rough  drawing  is  shown  of  the  parts  of  the  spec- 
troscope that  receive  light  and  prepare  it  for  analysis.  To  the 
right  is  the  upper  part  of  the  axis  of  the  heliostat  with  its  mirror, 
which  is  revolving  from  east  to  west  to  counteract  the  rotation 
of  the  earth.  Beams  of  light  are  falling  upon  it  from  the  sun 
and  the  brilliant  mirror  reflects  them  through  the  slit,  i-ioooth  of 
an  inch  in  width,  and  projects  the  rays  upon  the  lens  in  the 
opposite  end  of  the  tube.  The  lens  forms  a  clear  cut  image  of 
the  open  slit  upon  the  ruled  surface  of  the  diffraction  grating, 


Cut.  9.     Mirror  of  Heliostat,  Collimator  and  Diffraction  Grating. 

which  image  is  the  same  size  as  the  slit,  not  being  magnified  by 
the  convex  lens,  because  the  slit  is  in  its  principal  focus.  After 
more  than  a  century  of  ever-increasing  mechanical  accuracy,  at 
last  a  perfect  image  of  a  slit  is  had. 


RAD  I  A  NT     ENERGY.  39 

It  might  be  thought  an  easy  matter  to  make  an  opening 
with  sides  exactly  parallel  and  straight,  but  to  make  a  straight 
line  is  a  task  of  great  difficulty.  The  grating  is  a  flat  piece  of 
speculum  metal,  and  to  make  a  flat  surface  is  far  more  trying 
to  mechanics  than  to  make  a  straight  edge.  The  ruled  surface 
is  i  i -2x1  7-8  inches  and  is  ruled  14,438  to  the  inch.  To  rule 
it  required  several  days  and  nights  incessant  work  in  a  constant 
temperature  room. 


Cut  10.     Grating.     Showing  Incident  Rays,  and  Wave  Fronts  after 
Diffraction  and  Reflection. 

The  metal  plate  is  three-eighths  of  an  inch  thick,  and  in  figure 
7,  cut  10,  is  seen  lying  on  its  back,  showing  the  groves  as  they 
were  cut  with  a  diamond  point.  The  grating  is  superior  to 
the  prism  in  the  fact  that  it  makes  a  normal  spectrum.  Each 
wave  falls  into  its  proper  place,  which  is  not  true  of  the  prismatic 
spectrum. 


Cut  10A.     Fig.  7  the  Diffraction  Grating;  Fig.  13,  Prism. 

The  diffraction  grating  is  one  of  the  most  valuable  of  human 
possessions,  it  has  expanded  knowledge  more,  perhaps,  than 
any  one  discovery,  unless  the  calculus  may  be  classed  with  it  in 
power.  So  numerous  and  important  are  the  record  breaking 


4-0  RADIANT     ENERGY. 

discoveries  made   with   the  grating-  that  its  action  on  radiation 
must  be  thoroughly  understood. 

DIFFRACTION   AND   INTERFERENCE. 

These  will  be  treated  as  identical  here ;  they  are  cardinal  facts 
in  nature,  and  their  study  has  taxed  the  resources  of  physicists 
and  mathematicians  since  Newton  produced  diffraction  rings. 
Light  is  a  wave  motion  in  the  corpuscles  discovered  by  Professor 
J.  J.  Thompson.  All  along  a  hypothetical  ether  was  postulated 
to  be  the  medium  of  transmission  of  all  radiant  energy — but 
Thompson's  negative  corpuscles,  saturating  the  universe,  meets 
every  requirement  of  the  electro-magnetic  theory  of  radiation, 
due  to  Maxwell. 

All  radiant  energy  is  conveyed  by  means  of  waves  in  cor- 
puscles, but  it  is  known  that  waves  interfere  with  each  other. 
If  two  waves  exactlv  alike  interfere,  both  are  totallv  destroyed. 


Cut  11.     Fresnel's  Mirrors. 

Drop  two  stones  in  water  at  some  distance  apart,  waves  will 
expand  in  circles ;  in  a  short  time  the  two  circles  will  collide ; 
but  if  two  similar  waves  in  opposite  phase  meet,  the  water  will 
be  at  rest  and  a  cork  floating  thereon  will  not  oscillate.  If  two 
water  waves  interfere,  rest  succeeds ;  if  two  light  waves,  darkness 

Stillness  in  water  corresponds  to  darkness  in  the  midst  of 
light,  for  light  added  to  light  may  produce  darkness. 

All  this  can  be  seen  in  cut  IT,  due  to  Fresnel,  where  9, 
TO,  ii — 2,  3,  4  are  on  the  surfaces  of  two  plane  mirrors  hinged 
at  the  centre.  Their  reflecting  surfaces  are  nearly  in  the  same 


RADIANT     ENERGY.  4i 

straight  line,  the  inclination  angle  being  but  little  less  than  180 
degrees.  At  5,  is  the  radiant,  a  brilliant  point  or  slit,  while 
6,  7,  8,  is  a  white  screen,  and  I  is  a  curtain  so  that  light  from 
5  will  not  go  direct  to  6,  8,  and  obscure  the  light  from  the 
mirrors.  Its  use  leads  to  startling  results.  Let  light  of  any 
one  wave-length — say  blue — radiate  from  5,  strike  both  mirrors 
as  shown  and  be  reflected  to  the  white  card  6,  8.  One  point 
on  each  mirror  as  9  and  2  may  be  chosen  so  that  the  ray  5,  9 
added  to  9,  8,  shall  equal  in  length  the  ray  5,  2  plus  2,  8.  Then 
a  bright  spot  of  blue  light  will  appear  at  8.  This  is  because 
the  waves  leave  5  and  arrive  at  8  in  the  same  phase.  But  if  the 
ray  5,  10,  plus  TO,  7,  and  5,  3,  plus  3,  7,  differ  by  half  a  wave- 
length, a  dark  spot  is  seen  at  7.  Blue  waves  meet  at  unlike 
phase  and  destroy  oscillation.  The  hollow  of  one  comes  opposite 
to  the  crest  of  another,  the  motion  of  corpuscles  is  quenched, 
the  waves  interfere  and  both  are  destroyed. 

Thus  the  undulatory  theory  of  light  was  proven,  for  matter 
added  to  matter  cannot  destroy  both — light  is  therefore  not  mat- 
ter. And  there  will  be  alternate  bright  and  dark  spaces  on 
cither  side  of  6  and  8,  cut  n.  If  the  radiant  5,  gives  white 
light,  there  will  be  no  dark  spots,  but  every  possible  color  will 
take  their  places  and  the  cause  must  be  known  or  the  formation 
of  an  interference  or  diffraction  spectrum  cannot  be  compre- 
hended and  the  secret  processes  of  nature  remain  undiscovered 
forever. 

CAUSES  OF  INTERFERENCE   SPECTRA. 

Figure  i,  cut  12,  is  an  enlarged  view  of  the  rays  5,  10,  7  and 
5,  3,  7,  in  cut  IT.  Ray  5,  10,  7,  in  cut  12,  shows  5  waves,  and 
5>  3>  7>  5l/2-  They  interfere  and  destroy  each  other's  motion, 
hence  a  dark  spot  appears  at  7.  The  corpuscles  at  7  are  actuated 
by  equal  motions  in  opposite  directions.  They  remain  at  rest 
for  the  motions  are  in  directions  of  the  arrows.  The  darkness 
appears  if  one  kind  of  light,  as  violet,  is  used,  but  if  white  light 


4.2  RADIANT     ENERGY. 

is  reflected,  then  any  color  may  appear  at  7,  which  color  de- 
pends on  the  angle  of  the  light,  incident  on  the  mirrors.  For 
the  next  ray  to  5,  10,  7  and  5,  3,  7  might  not  differ  by  half  a 
wave-length,  and  not  interfere,  and  therefore  fall  on  the  vacant 


Cut  12.     Enlarged  Rays    from  Cut  11. 

space  filling  it  with  its  own  color  and  so  for  all  the  countless 
millions  of  waves  of  white  light  that  fall  on  the  mirrors.  Some 
will  be  quenched  and  some  augment,  and  build  up  a  long  colored 
band,  a  continuous  spectrum. 

Thus  in  figure  2,  cut  12,  two  rays  are  shown  in  harmonic 
oscillation,  the  arrowheads  at  the  end  point  in  the  same  direction, 
and  an  illuminated  band  is  seen  at  12.  The  spectrum  there- 


cut  13.     Diffracting  I^ight  over  edge  of  razor. 


fore  is  not  as  bright  as  the  radiant,  for  so  many  waves  are 
destroyed,  the  spectrum  from  the  sun  is  not  bright,  it  is  easy 
on  the  eyes  and  beautiful. 


RADIANT     ENERGY.  43 

DIFFRACTION. 

In  cut  13,  the  diffraction  or  breaking  of  light  is  shown 
where  light  from  the  lens  is  seen  diverging  to  the  screen,  but 
half  is  cut  off  by  he  edge  of  a  razor  or  sharp  knife.  When 
the  primary  wave  hits  the  edge  of  the  knife,  a  new  set  of 
waves  is  set  up  on  the  particles  of  metal,  and  they  radiate  light, 
some  above  and  some  below,  as  seen  on  the  screen.  One  cir- 
cular wave  front  is  shown  moving  away  from  one  rough  saw- 
tooth on  the  edge  of  the  razor,  and  two  in  the  original  wave 
series.  These  and  millions  more  interfere  and  break  up  the 
light,  for  diffraction  is  interference.  If  the  light  used  is  of 
one  kind,  as  orange,  black  spaces  and  orange  will  appear  on 
screen.  If  white  light,  the  screen  shows  colored  fringes  in  order 
of  wave  lengths.  But  the  razor's  edge  corresponds  to  the  eleva- 
tion of  metal  between  two  grooves  shown  in  the  vertical  grating, 
cut  9,  and  in  figure  7,  loA.  And  all  the  inclined  sides 
of  the  grooves  correspond  to  the  inclined  mirrors,  cut  u.  And 
this  is  the  philosophy  of  the  grating  in  the  most  primitive  form, 
where  if  it  were  being  treated  mathematically,  one-tenth  of  the 
space  would  be  required  that  is  taken  by  this  multitude  of 
words.  Cut  10  shows  four  waves  diffracted  from  the  eleva- 
tions, all  interfering  on  their  wave  fronts,  and  two  coinciding 
in  phase  reflected  from  the  sides  of  the  depressions.  This  is  the 
making  of  that  priceless  object,  a  spectrum. 

Refraction  is  seen  in  all  its  glory  in  the  diamond,  and  ordi- 
narily in  the  prismatic  pendants  from  chandeliers,  gas  fixtures, 
and  lamps,  and  in  cut  glass. 

Diffraction  is  on  display  in  the  peacock's  feathers,  on  the 
thin  striae  of  shells,  and  on  films  of  oil  on  water.  They  both 
cause  interference  and  colors.  Without  them  the  earth  and  all 
things  therein  would  lose  their  beauty. 


44  RADIANT     ENERGY. 


VI. 

ANALYSIS  OF  ENERGY  BY  MEANS  OF  THE  SPEC- 
TRUM. 

"It  appears  to  me  that  what  we  call  the  principle  of  heat  is  im- 
mortal— that  it  knows  all,  sees  all,  hears  all,  both  in  the  past  and  in 
the  future.  At  the  time  when  all  was  confusion  the  greater  part  of  this 
principle  rose  to  the  circumference  of  the  universe.  It  is  this  that 
the  ancients  have  called  ether." — Hippocrates. 

All  the  preceding  chapters  have  led  to  the  projection  of  a 
brightly  illuminated  image  of  the  slit  on  the  grating.  Energy 
falling  on  this  thin  band  is  worthy  of  attention  of  the  highest 
type  of  intellect  that  has  appeared. 

The  slit  and  its  resultant  image  are  filled  with  countless 
quadrillions  of  waves,  mixed  in  apparently  hopeless  confusion. 
To  make  use  of  the  wonderful  power  of  the  grating,  the  image 
must  be  viewed  with  a  telescope  inclined  to  its  surface.  If  not 
inclined,  then  dispersion  of  the  energy  into  separate  waves 
would  not  be  seen  and  analysis  could  not  be  made.  Each  wave 
length  must  be  examined  by  itself.  And  so  small  is  the  image 
of  the  slit  and  so  narrow  the  spectral  band  that  it  must  be  magni- 
fied. Thus  the  one  lens  of  the  collimator  forms 'an  image  with- 
out enlargement;  the  lenses  of  the  telescope  magnify.  The  result 
is  a  long  belt  of  the  most  gorgeous  colors  from  short-violet  to 
long-red  waves,  and  if  white  light  enters  the  slit  the  spectrum  is 


RAD  I  A  N  T      E  N  ti  R  C  Y. 


45 


continuous — without  break — that  is,  every  color  between  V  and 
R  is  present.  For  if  one  tint-rate  was  missing,  a  black  line — 
an  image  of  the  slit — would  cross  the  band  at  right  angles.  This 
must  be,  for  all  the  waves  are  separated  by  the  rulings  on  the 
grating,  and  there  are  none  to  fill  their  places.  This  is  a  corner- 
stone in  spectroscopy. 


Cut  14. 


This  can  be  understood  from  cut  14,  where  the  rough  out- 
lines of  a  spectroscope  are  shown  as  seen  by  a  person  standing 
on  a  chair  and  looking  straight  down.  A  pencil  of  energy  from 
the  sun  or  any  substance  being  analyzed  by  means  of  the  energy 
it  radiates,  is  seen  reflected  from  the  mirror  through  the  slit  and 
lens  of  the  collimator  and  falling  on  the  grating.  The  top  edge 
of  the  grating  is  shown.  It  stands  on  a  revolving  table  and 
can  be  turned  through  any  angle  as  shown  by  the  dotted  lines. 
The  edges  of  the  table  are  ruled  into  360  degrees  and  parts  of 
a  degree  which  are  still  closer  read  by  vernier  and  microscope. 
The  angle  the  grating  makes  with  the  incident  ray  can  be  meas- 
ured with  accuracy.  The  elevations  and  depression  on  the  grat- 
ing diffract — break  up — and  disperse — separate — all  waves  ac- 
cording to  their  lengths,  sort  them  out  by  themselves  and  reflect 
them  all  upon  the  object-glass  of  the  view  telescope. 


46  RADIANT     ENERGY. 

The  telescope  turns  in  all  directions  around  the  center  of 
the  grating — that  is,  about  the  image  of  the  slit  as  a  center,  and 
these  angles  can  be  measured  with  precision.  The  angles  of 
deviation  are  of  great  use,  for  finding  by  trigonometrical  formulas, 
the  lengths  of  the  waves.  These  waves  can  be  measured  with  ex- 
treme accuracy,  the  objective  of  the  telescope  renders  the  in- 
cident diverging  rays  parallel  and  projects  the  cylinder  upon 
the  fieldglass  of  the  eye  piece  as  shown.  This  lens  makes 
the  parallel  rays  converge  and  fall  on  the  eye  lens,  which  further 
converges  and  causes  them  to  cross  just  in  front  of  the  lens 
in  the  eye,  which  projects  an  image  of  the  spectrum  on  the 
retina  as  drawn ;  but  the  observer  thinks  the  image  is  far  from 
the  eye  in  space  near  the  middle  of  the  telescope  shown  in  the 
dotted  spectrum  and  the  letters  V  I  B  G  Y  O  R. 

The  size  of  this  imaginary  spectrum  depends  on  the  angle 
made  where  the  rays  cross  between  the  glass  lens  and  lens  in 
the  eye.  For  the  side  of  the  retina  marked  A,  sees  red  light 
in  the  direction  R ;  and  the  side  of  the  retina  marked  R,  sees 
violet  light  in  the  direction  V,  and  it  is  a  principle  in  optics  that 
the  observer  imagines  an  object  to  be  in  the  direction  in  which 
rays  fall  on  the  retina.  If  white  light  enters  the  slit,  the  eye 
will  see  all  possible  colors  from  R  to  V,  but  if  any  waves  are 
missing,  a  black  line  will  be  seen,  as  in  figure  2,  cut  14,  where 
all  the  blue  waves,  two  red  and  one  violet,  are  absent. 

All  phases  of  matter,  when  hot  enough  for  corpuscles  to 
have  room  sufficient  in  which  to  oscillate  at  their  own  rate,  pro- 
ject spectra  consisting  of  bright  lines  only,  no  two  phases  being 
able  to  cast  identical  sets  of  lines. 

This  is  one  of  the  chief  facts  known.  Heat  sodium,  for 
instance,  hot  enough,  either  by  a  Bunsen  burner,  by  the  electric 
arc  or  spark,  and  hold  it  close  to  the  slit,  and  the  conditions  rep- 
resented in  cut  14,  figure  3,  will  be  seen.  Two  bright  lines  in  the 
yellow  flash  out,  and  all  other  portions  of  the  spectrum  will  be 


RADIANT     EN  ERG  Y.  tf 

black.  This  is  because  the  metal  sodium  is  unable  to  vibrate  in 
more  than  two  rates,  and  cannot  set  up  any  other  waves,  hence 
their  places  must  be  dark.  So  far,  more  than  80  conditions  in 
which  matter  exists,  have  been  found,  and  their  bright  lines  care- 
fully measured  and  mapped.  These  lines  and  bands  are  the  nat- 
ural alphabet.  He  who  desires  to  know  of  the  universe  must 
read. 

There  are  42,175  long"  sodium  waves  and  43,078  short  in  one 
inch.  The  rate  of  the  long  waves  is  495  million  million,  and 
of  the  short  507.  million  million  oscillations  per  second.  This 
is  known  to  be  true,  and  may  be  demonstrated  by  analysis,  either 
of  the  energy,  or  the  sodium  as  one  pleases  to  call  it.  The 
Roentgen  or  X-rays  are  much  more  rapid. 

The  metal  sodium  is  the  basis  of  common  salt.  The  ocean 
spray  is  evaporated  in  the  air,  leaving  minute  particles  of  salt 
in  suspension,  filling  the  atmosphere  around  the  globe.  So  deli- 
cate is  spectrum  analysis  that  it  is  almost  impossible  to  be  rid 
of  the  two  yellow  sodium  lines,  while  making  analysis  of  other 
metals.  Bunsen  found  that  the  one  14-millionth  of  a  milli- 
gram of  sodium  projected  the.  well-known  yellow  lines.  The 
rustling  of  a  paper  or  movement  of  the  hand  through  the  air 
arouses  a  hurricane  of  the  particles,  these  fall  into  the  source 
of  heat,  are  instantly  torn  into  corpuscles  hundreds  of  millions 
of  times  smaller,  and  these  set  up  waves  that  enter  the  slit. 
Lithium  vibrates  with  two  rates,  one  yellow  and  the  other  orange. 
Iron  beats  with  about  480  different  velocities,  while  the  metal 
thallium  has  but  one  rate. 

IDENTIFYING   THE    LINES. 

Each  line  cast  by  any  state  of  matter  must  be  capable  of 
being  identified  by  inspection.  The  distances  between  the  lines, 
the  widths  of  the  lines  themselves,  and  their  positions  in  the 
spectrum,  are  invariable  for  the  same  purity,  temperature,  pres- 
sure and  grating. 


4S  RADIANT     ENERGY. 

Widths,  spaces  and  positions  are  measured  by  means  of  a 
micrometer  placed  in  the  eye-piece.  This  is  an  instrument  com- 
posed of  two  spider  webs  crossed  like  an  X  and  stretched  across 
a  moveable  frame  in  the  field  of  view ;  that  is,  they  are  in  front 
of  the  spectrum  and  can  be  moved  by  rotating  the  screw  so  they 
will  bisect  any  line  or  space  and  measure  all  with  an  accuracy 
almost  past  belief.  It  has  been  agreed  to  by  spectroscopists 
throughout  the  world  to  adopt  the  universal  standard  of  ten- 
millionths  of  a  millimeter  in  which  to  express  wave-lengths  of 
radiant  energy.  The  spicier  lines  must  be  illuminated  by  a  side 
light  to  render  them  visible  under  all  circumstances.  For  they 
are  so  thin  that  they  are  not  at  all  times  visible  when  in  front 
of  the  colors  of  the  spectrum. 

This  is  the  office  of  the  electric  lantern,  2,  3,  cut  8. 


Cut"15.     Spectroscope  in  I^owe"  Observatory. 

In  cut  15,  is  shown  the  complete  spectroscope  in  the  Lowe 
observatory.  The  grating  is  shown  between  the  objectives  of 
the  collimator  and  view  telescope,  while  the  micrometer  is  seen 
to  the  left,  attached  to  the  eye-piece  of  the  telescope.  The  slit  is  at 
the  right,  and  the  edge  of  the  circular  ruled  turntable  is  shown 
under  the  grating  in  the  center.  The  entire  instrument  stands  on 


RADIANT     ENERGY.  49 

three  leveling  screws  to  centre  the  slit  on  the  mirror  of  the  heliostat 
in  the  bright  sunshine  outside.  The  ruled  screw-head  is  not  seen  in 
the  cut,  being  on  the  opposite  side  of  the  tube ;  but  the  window 
of  the  micrometer  is  seen  on  this  side.  The  little  tube  attached 
to  this  side  of  the  telescope  is  an  electric  lantern,  in  which 
is  placed  a  minute  (i  c.  p.)  incandescent  bulb  with 
wires  leading  to  a  battery  cell.  When  the  current  is  on,  the 
light  passes  to  a  right-angled  or  total  reflection  prism  in  the 
other  end  of  the  tube,  where  it  is  reflected  through  the  win- 
dow pane  shown,  and  strikes  the  webs  in  front  of  the  eye.  They 
look  like  minute  fibers  of  glittering  white  and  are  clearly  visible 
against  any  color  behind  them. 

Each  spectroscope  must  be  made  the  subject  of  experiment 
until  the  value  of  one  turn  of  the  screw  is  found  in  ten-millionths 
of  a  millimeter,  and  is  called  the  constant  of  the  micrometer. 
One  millimeter  is  very  nearly  equal  to  the  i-25th  of  an  inch,  and 
therefore  it  is  with  25-millionths  of  an  inch  that  the  modern 
spectroscope  deals.  It  is  hoped  that  the  word  inch  will  disappear 
from  scientific  literature. 

When  any  phase  of  matter  casts  a  spectrum,  it  is  better  to 
let  its  light  make  a  graph  on  a  sensitive  plate  than  to  make  a 
map  by  hand  drawing.  The  natural  writing  is  more  accurate, 
and  the  lines  can  be  measured  with  a  measuring  machine  as  well 
as  by  the  web  micrometer.  Thus  photography,  that  majestic 
science,  is  the  constant  companion  and  helper  of  the  spectroscopist 
and  astronomer. 

In  cut  15,  the  telescope  and  collimator  are  opened  at  a  very 
wide  angle  to  give  a  view  of  the  grating,  both  objectives  and 
the  lantern.  The  spectroscope  could  not  be  used  at  so  wide  an 
angle;  the  telescope  must  be  turned  around.  The  slit  is 
shown  on  the  end  of  the  collimator  to  the  right.  On  the 
table  below  is  a  tube  with  lens  in  one  end,  which  lens  forms 


jo  RADIANT     ENERGY. 

% 

an    image  of   any   luminous   object   on  the   slit,   so   any   part   of 
the  image  may  be  examined  instead  of  the  whole  object. 

This,  then,  is  an  analyzing  spectroscope,  where  the  slit  with- 
out the  lens  between  it  and  the  object  would  be  an  integrating 
instrument.  On  the  table  to  the  left  is  a  different  kind  of  a  slit 
from  that  of  the  collimater.  It  is  for  analysis  of  energy  direct 
from  the  sun  and  will  be  treated  in  Part  II,  on  astronomical  spec- 
troscopy. 


RADIANT     ENERGY.  5/ 


PART    II. 

VII. 
ASTRONOMICAL  SPECTROSCOPY. 

"Anaxagoras  teaches  that  the  ambient  ether  is  of  an  igneous  origin, 
and  by  the  force  of  its  gyratory  motion  it  tears  off  blocks  of  stone,  renders 
them  incandescent,  and  transforms  them  into  stars." — Plutarch. 

The  elementary  notes  I  to  VI  inclusive,  dealt  with  diffrac- 
tion, inflection,  and  dispersion  of  energy  into  a  spectrum.  Rates 
were  from  395  to  764  million  million  per  second — commonly  called 
light.  It  was  shown  that  swings  of  corpuscles  to  and  fro  like 
a  pendulum  give  rise  to  disturbances,  which  are  imparted  to 
the  next  and  next  and  so  on  with  a  speed  in  a  straight  line 
always  of  186,000  miles  per  second  in  space,  and  with  less  vel- 
ocity in  transparent  and  refracting  media.  It  was  seen  that  white 
light  is  composed  of  an  infinite  nu  Tiber  of  different  rates  of 
swing — called  colors,  and  that  these  vibrations  could  be  sorted  and 
placed  by  themselves  by  dispersing  apparatus  such  as  prisms  and 
diffracting  gratings.  But  when  so  separated  it  was  found  by  a 
century  of  study  that  different  phases  in  which  matter  exists 
could  be  detected  by  merely  analysing  the  waves  they  set  up. 
For  each  condition  of  matter  when  its  corpuscles  are  vibrating 
at  their  own  characteristic  rates  cause  different  sets  of  waves, 
varying  in  lengths,  amplitudes  and  periods  of  oscillation. 

All  of  the  eighty  or  more  modes  oi  matter  have  been  made 
to  vibrate  in  front  of  the  slit  by  heat,  as  from  the  electric  arc 
between  carbon  terminals,  in  whose  plus  crater  metals  were  placed, 


52 


RADIANT     ENERGY. 


which  were  at  once  vaporized,  forcing  corpuscles  to  undulate  in 
their  own  free  paths ;  or  by  the  terrific  heat  of  the  stored  up 
electric  sparks  through  an  air  gap  between  terminals  of  metals 
under  analysis  and  held  before  the  slit.  The  current  is  passed 
through  an  induction  coil,  and  if  high  potential  is  desired  for 
the  refractory  metals,  Leyden  jars  with  air  spaces  are  set  up 
tandem  in  the  secondary  circuit  of  the  coil,  which  turn  the 
most  obdurate  metals  to  gas,  and  set  the  corpuscles  into  rapid 
pulsation,  sending  their  own  waves  to  slit,  grating  and  spectrum. 
Also  the  heat  of  the  oxy-hydrogen  jets,  gas  jets,  Bunsen  jets, 
air  and  coal  gas,  as  well  as  alcohol  flames  have  been  employed 
to  set  corpuscles  swinging,  the  object  of  all  being  to  get  their 
energy  in  the  spectral  band — into  a  state  of  isolation  for  exam- 
ination by  themselves.  The  entire  process  is  termed  spectrum 
analysis,  or  spectrochemistry. 

But  all  this  took  place  among  familiar  states  of  matter  here 
on  the  earth.  The  whole  three  centuries  of  incessant  work — even 
if  everv  condition  on  the  earth  were  analysed,  would  amount  to 
little  since  the  earth  in  space  is  smaller  than  one  of  Thomson's 
corpuscles  in  proportion  to  an  ordinary  room,  and  an  "atom" 
of  hydrogen — the  smallest  physical  body  known,  is  1,000  times 
more  massive  than  the  corpuscle.  So  if  men  could  not  enlarge  their 
sphere  of  action  and  get  away  from  this  terrestrial  sphere — the 
entire  labor  of  the  human  species  from  appearance  here,  would 
be  exceeding  small.  Hence  the  whole  subject  of  spectrochem- 
istry, with  its  extensive  literature,  with  its  record  of  arduous 
"oil  day  and  night,  with  incessant  vigil  of  the  tiny  electric  spark 
and  smaller  wave,  with  its  days  and  months  and  years  of  in- 
credible work  and  consummate  skill  of  body  and  brain,  the  finest 
yet  developed  on  the  planet — all  these  and  all  the  books,  whose 
titles  only  fill  a  large  volume,  all  must  be  passed  here  and  that 
other  branch  of  spectroscopy  taken  up,  the  astronomical. 

So  far  bright  lines  only  have  been  noticed,  luminous  as  they 


RADIANT     ENERGY.  53 

fell  in  their  regular  places  fresh  from  hot,  vibratory  corpuscles. 
But  in  1814  Fraunhofer  looked  at  the  solar  spectrum  with  a 
telescope  and  saw  "an  infinite  number  of  vertical  lines,  darker 
than  the  rest  of  the  spectrum,  and  some  of  them  appear  entirely 
black."  He  mapped  576.  (See  his  map  in  Fig.  4.)  He  died 
without  knowing  their  cause.  In  1822  Brewster  put  colored 
glasses  between  the  sources  of  light  and  the  slit.  The  entire 
spectrum  disappeared  except  the  waves  having  the  same  color  as 
the  glass.  Herschel  did  the  same  with  colored  glass  and  also  with 
rok  iv:l  liquids.  They  quenched  all  waves  except  those  they 
emitted.  If  white  light  be  passed  through  red  glass  the  whole 
spectrum  vanishes  except  red. 

In  making  researches  in  absorption  the  physicist  Brewster 
wrote :  "The  first  object  of  my  inquiries  was  to  discover  a  general 
law  of  chemical  analysis  in  which  simple  or  compound  bodies 
might  be  characterized  by  their  action  on  different  parts  of  the 
spectrum." 

He  said  there  must  be  absorption,  but  this  mighty  law  he 
failed  to  see  in  all  its  clearness — to  him  it  appeared  in  dim  outline 
like  a  ship  coming  out  of  mist.  The  human  mind  was  groping  in 
darkness  in  presence  of  one  of  the  chief  mysteries  of  nature.  This 
was  in  1833.  The  black  lines  in  the  solar  spectrum  were  absolutely 
inexplicable.  Becquerel  photographed  these  lines  in  1842  and 
Draper  in  1843. 

About  this  time  bc^an  one  of  the  most  extensive  series  of  re- 
searches in  the  history  of  the  world.  Arduous  and  long  con- 
tinued. Every  physicist  knew  that  a  magnificent  law  was  hidden 
in  the  black  solar  lines. 

PRODUCTION  OF  BLACK  LINKS  BY  EXPERIMENT. 

Spectroscopists  began  to  imitate  the  sun.  Foucault  in  1849 
projected  white  light  through  yellow  sodium  light  in  an  electric 
arc  and  produced  two  black  lines  in  the  exact  places  of  the  two 


54  RADIANT     ENERGY. 

yellow  on  a  screen.  For  some  reason  this  did  not  awaken  the 
world,  although  it  was  the  beginning  of  celestial  chemistry.  Men 
had  to  wait  ten  years  until  that  eventful  and  auspicious  day,  Octo- 
ber 27,  1859,  when  KirchhofFs  immortal  work  was  read  to  the 
Academy  in  Berlin.  Here  are  a  few  of  his  words : 

"I  formed  a  solar  spectrum  by  projection,  and  allowed  the 
solar  rays  concerned,  before  they  fell  on  the  slit,  to  pass  through 
a  powerful  salt  flame.  If  the  sunlight  were  sufficiently  reduced, 
there  appeared  in  place  of  the  two  dark  lines,  D,  two  bright  lines ; 
if,  on  the  other  hand,  its  intensity  surpassed  a  certain  limit,  the 
two  dark  lines,  D,  showed  themselves  in  much  greater  distinctness 
than  without  the  employment  of  the  salt  flame." 

These  words  have  the  same  relation  to  spectroscopy  of  the 
sun  and  stars  that  the  Constitution  has  to  people  of  the  United 
States.  They  are  fundamental,  historic,  wonderful. 

The  basic  fact  can  be  understood  by  means  of  Cut  16,  where 
is  shown  a  lamp  burning  alcohol  which  makes  great  heat  with 
little  light.  The  wick  has  been  saturated  with  a  solution  of  com- 
mon salt  and  dried.  The  heat  volatilizes  the  metal  sodium,  tearing 
its  particles  away  from  their  union  with  chlorine.  They  vibrate  at 
their  own  rate,  and  fill  the  entire  flame  with  dense  yellow  light. 
If  now  this  light  be  passed  through  the  slit,  two  brilliant  yellow 
lines  are  seen  at  A,  and  the  remainder  of  the  spectrum  is  dark, 
because  sodium  is  unable  to  vibrate  in  more  than  two  rates.  Cut 
1 6,  Fig.  2.  If  strong  white  light  concentrated  into  a  beam  be 
sent,  say  from  an  electric  arc,  through  the  flame,  the  bright  yellow 
lines  vanish  and  all  the  other  parts  of  the  spectrum  reappear,  ex- 
cept in  the  two  places  occupied  by  the  bright  lines  which  are  now 
black.  Fig.  3.  And  if  instead  of  the  electric  light,  sunlight  be 
sent  through  the  yellow  flame,  the  two  black  lines  already  in  the 
yellow  region  of  the  solar  spectrum  become  blacker  than  before, 
Fig.  4. 


RADIANT     ENERGY. 


55 


WHITE  SCREEN" 


Cut  Id.     Klectric  Carbons,  Alcohol  Flame,  and  Absorption  Spectra. 


56  RADIANT     B  N  B  R  G  Y. 

If  a  piano  wire  tuned  to  say  C,  be  stretched  across  the  end 
of  a  long  room,  and  many  other  wires  all  tuned  to  C  be  stretched 
somewhere  near  the  other  end  of  the  room,  with  an  observer 
standing  behind  them — then  if  the  one  distant  string  be  set  in  vi- 
bration the  listener  will  not  hear  it,  but  will  hear  the  C  note  in  all 
the  wires  near  him.  The  many  wires  cut  the  waves  of  the  one 
other  out  of  space,  ami  quench  them  by  appropriating  their  energy 
to  their  own  use.  Sound  any  other  wire  near  the  one  C  wire,  and 
the  listener  behind  the  screen  of  wires  will  hear  any  note  whatever 
except  C.  The  wires  in  the  screen  are  unable  to  vibrate  in  any 
other  rate  than  that  required  to  sound  C.  So  with  the  corpuscles 
of  sodium — they  are  tuned  to  yellow  with  two  rates  and  cannot 
oscillate  at  any  others.  Hence  the  yellow  flame  lets  every  other 
color  rate  through  without  hindrance  and  absorbs  the  yellow, 
producing  black  on  the  screen  A. 

In  cut  1 6  the  prism  or  grating  is  not  drawn.  Fig.  I  is  a 
continuous  spectrum  as  cast  by  the  electric  arc  alone.  Fig.  2  is 
that  of  sodium  alone.  Fig.  3,  .that  of  the  electric  white  light 
shining  through  sodium  yellow  light.  Fig.  4  is  a  minute  portion 
of  the  spectrum  of  the  sun  near  the  sodium  lines,  showing  others. 
But  the  two  sodium  lines  always  seen  black  in  the  sun,  fall  in  the 
exact  places  occupied  by  the  two  bright  lines  of  sodium. 

LAW   III. 

All  modes  of  matter  when  vibrating  at  their  own  rates  absorb 
the  same  waves  they  are  able  to  generate. — Kirchhoff. 
The  mystery  of  the  sun  is  not  yet  explained. 


RADIANT     ENERGY.  57 


VIII. 

ABSORPTION. 

"One  nature  delights  in  another;  one  nature  overcomes  another,  one 
nature  overrules  another,  and  the  whole  of  them  are  one.'' — Book  of 
Stone,  Temple  of  Memphis,  Archaic  Egyptian,  Synesius  copy. 

The  extinction  of  energy  in  space  or  its  absorption  and  con- 
sequent disappearance  in  matter  is  a  deep  seated  fact  in  Nature. 
The  appropriation  and  selection  of  waves  by  matter  and  their 
eventual  return  to  space  constitute  the  life  of  the  universe,  the 
ebbing  and  flowing  of  cosmical  tides.  In  treating  of  that  minute 
fraction  of  the  total  and  invariable  quantity  of  energy,  usually 
called  light,  it  is  well  to  recall  that  if  matter  quenches  every  light 
wave  that  penetrates  below  its  surface,  it  is  said  to  be  jet  black. 
A  black  object  is  seen  merely  from  a  small  portion  of  the  incident 
light  reflected  from  its  extreme  outside  inconceivably  thin  layer 
of  particles.  The  processes  taking  place  in  the  next  layer  de- 
stroys light  so  far  as  seeing  it  is  concerned,  and  in  the  present 
state  of  science  seems  to  be  lost — falling  on  some  bodies ;  but 
if  the  waves  strike  a  growing  plant  they  do  work.  They  are  said 
to  be  absorbed,  and  a  green  leaf  absorbs  all  waves  except  the 
green,  which  are  reflected,  and  a  red  rose  absorbs  all  waves  but 
red.  Thus  there  is  no  color  on  earth — all  colors  are  in  the  light. 

Particular  attention  must  be  given  to  absorption  in  the  spec- 
trum of  any  light  whatever.  The  subject  is  a  mighty  one,  for  by 


5$  RADIANT     ENERGY. 

this  means  only  can  the  key  to  read  the  letters  of  the  universe 
be  found.  Every  absorption  letter  is  made  up  of  short  vertical 
black  lines  in  the  spectrum  of  either  our  own  or  the  multitudes 
of  other  suns  in  measureless  wastes  of  space — that  is,  the  stars 
(suns),  are  read  by  means  of  waves  that  are  absent,  waves  that 
would  have  reached  the  earth  as  bright  light  had  they  not  been 
cut  out  by  some  means,  which  is  now  the  problem  to  be  solved— 
the  capital  problem  so  far  solved  by  man. 


Cut  17.     Six  Spectra  and  Scale. 


In  cut  17  an  attempt  is  again  made  to  clear  up  the  question 
of  absorption,  or  destruction  of  wave  motion.  In  Fig.  i  the  paper 
appears  white  because  white  light  falls  upon  it  and  is  reflected 
without  change.  That  is,  the  waves  are  not  separated,  but  are 
mixed  in  confusion,  and  a  jumble  of  all  possible  waves  appears 
white.  In  2  there  is  shown  a  continuous  spectrum,  all  colors  from 
red  to  violet  are  present.  (It  is  difficult  to  explain  spectroscopy 
without  diagrams  in  colors.)  The  cause  of  this  is  the  waves  have 
been  separated  by  a  prism  or  grating;  for  when  waves  are  dis- 
persed colors  appear,  for  each  wave  vibrates  at  its  own  speed, 
free  from  all  others.  In  Fig.  3  blue  is  missing,  black  results,  for 


&'• 
i;jM!V 


RADIANT     ENERGY.  59 

no  other  waves  can  fill  that  space;  none  but  blue  have  such  re- 
frangibility  and  cannot  be  bent  into  that  vacant  region.  Indigo 
and  violet  are  refracted  by  a  prism  or  diffracted  by  a  grating  too 
far  to  the  left,  and  the  other  colors  not  far  enough  to  fall  where 
blue  alone  is  able.  In  4  violet  and  red  are  wanting  and  four 
waves  of  the  green  also.  These  attempted  to  pass  through  a  gas 
that  may  have  been  invisible  or  transparent  to  all  colors  except 
green,  or  possibly  they  hit  against  a  block  of  wood,  both  equally 
opaque.  In  5  the  entire  spectrum  has  vanished,  by  their  having  en- 
deavored to  pass  through  an  absorbing  medium  as  black  glass,  or 
through  a  great  thickness  of  clear  glass  or  of  water.  At  all 
events  they  are  absent  and  black  appears.  In  6  a  crude  spectrum 
of  the  sun  is  shown  with  a  few  black  lines  only  out  of  over  8,000 
known.  Since  the  spectrum  did  not  fall  on  a  surface  able  to 
quench  all  the  waves,  for  many  appear,  and  since  a  number  of 
black  lines  are  seen,  the  solar  rays  have  surely  traversed  a  gas 
having  power  to  select,  quench  or  absorb  all  the  missing  undu- 
lations whose  normal  spaces  are  occupied  by  black.  The  mi- 
crometer cannot  be  well  shown  here,  so  a  rule  is  drawn  at  the 
bottom  of  the  series  of  6  spectra.  A  straight  edge  placed  on  the 
1 6  in  the  rule  will  coincide  with  the  black  line  in  the  green  rates 
in  4,  and  likewise  with  ruling  No.  17.  Evidently  there  is  no  mode 
of  matter  in  the  sun  whose  corpuscles  swing  with  these  rates  or 
the  waves  have  been  counteracted  between  the  sun  and  earth. 
For  under  all  circumstances  these  two  lines  fall  at  16  and  17  on 
the  rule  with  the  same  prism  or  grating. 

Proof  will  be  given  in  a  note  on  solar  chemistry  that  these 
states  of  matter  really  are  incandescent  in  the  sun  and  that  the 
black  lines  are  truly  absorption  spaces — images  of  the  slit— black 
because  these  waves  did  not  enter  the  narrow  opening,  being 
absent  in  those  radiations  reaching  the  earth  from  the  sun,  not 
sent,  or,  if  emitted,  absorbed. 


60  RADIANT     ENERGY. 

IMITATING    THE    SOLAR    FURNACE. 

Ill  cut  1 8  is  seen  an  instantaneous  photograph  of  two  arc  light 
carbons  immediately  after  the  current  was  shut  off.  The  crater 
in  the  plus  or  lower  carbon  is  still  white  hot,  the  cavity  scooped 


Cut  18.     Graph  of  Arc  lyight  Carbons. 

out  by  the  flowjng  electricity  and  its  terrific  heat,  for  carbon  is 
the  most  difficult  of  all  modes  to  melt  or  vaporize.  Now,  if  the 
proper  phase  of  substance  is  thrown  into  this  crater  and  the  re- 
sulting waves  be  passed  through  the  slit,  the  two  lines  16  and  17 
in  Fig.  6,  in  cut  17,  can  be  exactly  matched,  if  the  two  spectra  are 


RADIANT     ENERGY. 


61 


placed  side  by  side — that  is,  the  lines  will  be  end  to  end  as  in 
cut  16.  This  is  the  same  as  saying  that  the  two  black  lines  in 
the  green  corresponding  will  be  filled  with  green  light  in  Fig.  4, 
in  cut  17.  In  the  present  state  of  spectroscopy  part  of  the  dark 
lines  in  the  spectrum  of  the  sun  can  be  filled  up  with  their  proper 
light  in  the  laboratory,  but  not  all.  There  are  black  lines  not  yet 
accounted  for — that  is,  no  mode  of  matter  yet  discovered  on  the 


Cut  19.     I^ockyer's  Klectric  Arc  and  Projection  Spectra. 

earth  will  set  up  the  right  waves  to  fall  in  these  vacant  places. 
At  present  a  most  exhaustive  search  is  constantly  being  made 
to  find  phases  that  will  oscillate  at  the  solar  rates  and  fill  the  lines 
with  bright  light.  Modes  have  been  found  in  the  sun  first,  and 
afterward  detected  here  on  earth.  These  will  be  given  in  a  note 
on  the  chemistry  of  the  sun. 

Cut    19   is   an   outfit    from   Lockyers    studies.      In   the   left 
stands  an  electric  lantern  containing  the  two  carbons  in  cut  18. 


62  RADIANT     ENERGY. 

Wires  enter  the  bottom.  To  the  right  is  a  lens  L.  Next  is  a 
Bunsen  burner  burning  city  gas  mixed  with  air  coming  in  along- 
side of  the  gas  below.  The  spectroscopist  is  holding  a  platinum 
spoon  in  the  hot  but  dim  flame — high  heat,  low  light ;  the  waves 
are  too  long  for  light.  The  heat  is  not  great  enough  to  melt  the 
platinum,  but  will  vaporize  the  less  refractory  metals. 

Place  a  piece  of  metal  in  the  spoon ;  when  it  oscillates  fast 
enough  the  flame  will  be  filled  with  its  corpuscles  and  will  be 
colored  with  the  color  that  the  metal  is  able  to  generate.  The 
metal  may  have  one  rate,  as  thallium,  or  many ;  but  whatever 
rates  it  may  have  the  prism  P  will  separate  them  and  project 
a  spectrum  on  the  screen  S  S.  And  the  spectrum  will  present 
bright  lines  due  to  the  metal.  It  will  not  be  continuous.  All 
parts  of  the  band  will  be  dark  except  where  the  thin  strips  of 
light — images  of  the  slit — fall.  Each  mode  of  matter  vaporized 
gives  a  different  set  of  lines.  Now,  when  the  bright  lines  are 
on  the  screen  turn  on  the  white  electric  light  from  the  lantern 
and  pass  it  straight  through  the  Bunsen  flame.  Instantly  all 
bright  lines  on  the  screen  turn  black,  and  all  black  parts  of  the 
spectrum  are  filled  with  light,  the  Bunsen  flame  allows  all 
waves  to  pass  through  except  those  rates  due  to  the  vaporized 
metal  within.  That  is  the  law  of  Kirchhoff. 

Cut  20  is  far  better  than  this  method  of  a  flame  in  the  open 
air.  At  the  left  is  an  apparatus  for  the  production  of  hydrogen 
gas.  Next  is  the  electric  lantern  as  in  19.  Then  comes  an 
iron  furnace  with  chimney  above.  A  long  iron  tube  passes 
directly  through  the  furnace,  and  can  be  brought  to  a  great 
heat.  The  tube  has  a  glass  window  at  each  end.  The  air  is 
expelled  from  the  pipe,  which  is  now  filled  with  hydrogen — to 
be  rid  of  oxygen.  Any  metal  whose  point  of  vaporization  is 
less  than  that  of  iron  is  put  into  the  vertical  tube  up  through 
the  roof  of  the  furnace  as  shown.  The  pieces  of  metal  slide 
down  into  the  tube  and  hydrogen.  The  fire  is  now  lighted  in 


RADIANT     ENERGY.  6j 

the  furnace  and  the  metal  is  turned  into  a  vibrating  gas.  Then 
the  powerful  white  light  from  the  electric  lamp  is  passed 
lengthwise  through  the  glass  ends  of  the  tube  and  falls  into  the 
slit  of  the  spectroscope  on  the  right  for  analysis.  Absorption 


Cut  20.     I,ockyer's  Absorption  Furnace  and  Spectroscope. 

bands  and  lines  can  be  measured  with  the  micrometer  and  re- 
corded. 

There  are  other  more  modern  ways  of  studying  absorption. 
And  the  absorption  lines  of  all  modes  of  matter  so  far  discovered 
are  tabulated. 


RADIANT     ENERGY. 


IX. 
EXPLORATION  OF  THE  UNIVERSE. 

"For  consider,  Purna,  that  great  vault  of  space,  the  sun  shines  forth 
and  there  is  light,  the  clouds  gather  and  there  is  darkness,  the  winds 
arise." — Kiounen  Sutra,  Chinese  Scriptures. 

"But  if  darkness,  light  and  sight  be  separate  and  independent,  one 
of  the  other,  then  if  you  remove  light  and  darkness,  there  is  nothing  left 
but  void  space." — Buddhistic  Sutra. 

In  cut  21  are  shown  three  of  the  most  valuable  instruments 
in  the  possession  of  scientific  men — three  mighty  engines  for 
the  conquest  of  nature.  They  explore  the  mysteries  of  the  si- 
dereal universe,  and  reveal  its  secrets.  Without  a  full  knowledge 
of  these  three  and  how  to  use  them,  man  must  have  forever  re- 
mained ignorant  of  the  vast  cosmical  structure  in  which  he  finds 
himself  an  inconceivably  minute  portion. 

The  dust  in  the  air  in  the  room  in  which  the  reader  may 
be  is  larger  in  proportion  to  the  space  in  the  room,  than  the  earth 
is  to  space  revealed  by  the  telescope. 

The  lenses  shown  bring  energy  into  the  slit  of  the  spectro- 
scope from  our  own  and  countless  suns  besides,  and  from  nebulae 
in  the  limitless  sea  of  space,  and  projects  the  telltale  waves 
upon  the  grating.  This  analyzes  them  and  makes  known  the  con- 
ditions of  matter  sending  the  tiny  undulations.  It  becomes  known 
what  the  structure  of  nature  is  composed  of.  And  that  other 
lever  to  pry  up  the  universe,  the  differential  and  integral  cal- 
culus, culminates  the  present  achievement  of  the  human  brain. 


RADIANT     ENERGY.  65 

Once  let  its  grasp  seize  the  mechanism  and  motions  of  suns  and 
solar  systems  or  anything  that  can  be  chained  to  the  servitude 
of  mathematics  and  all  is  revealed.  No  motion  can  escape 
its  searching  analysis ;  it  drags  forth  the  most  abstruse  and  hid- 


Cut  21.     Calculus,  Lens  and  Grating;  three,  mighty  engines  for  exploring 
the  universe. 

den  mysteries  of  matter  in  all  its  movements.  Without  these 
three,  men  today  would  be  all  unconscious  of  those  majestic  laws 
governing  the  sidereal  structure. 

CHEMISTRY    OF   THE   SUN. 

Having  brought  the  separate  parts  of  the  modern  spectro- 
scope together  into  a  complete  instrument,  it  is  time  now  to  use  it, 
beginning  with  that  fascinating  work,  the  chemistry  of  the  sun. 

The  sun  is    1,310,000  times  larger  than  the  earth,  but  the 


66  RADIANT     ENERGY. 

quantity  of  matter  is  only  333,426  times  that  contained  in  the 
earth.  How  the  mass  of  the  sun  was  found  cannot  be  given  in 
these  primitive  essays.  With  this  volume  and  mass  its  density  is 
only  .26  or  slightly  more  than  one-fourth  that  of  the  earth.  The 
sun  sends  out  in  stupendous  floods  in  all  directions,  energy,  solely 
in  the  form  of  waves.  It  sends  forth  2,220,000,000  times  more 
waves  than  are  encountered  by  the  earth. 

If  waves  interfere  by  odd  multiples  of  half  wave-lengths  they 
destroy  each  other,  or  if  they  hit  matter  in  these  odd  phases  they 
destroy  themselves,  but  if  they  strike  matter  in  even  phases  they 
do  an  incredible  amount  of  work.  They  sustain  every  activity  on 
earth  and  alone  keep  up  life.  But  men  might  have  existed  on 
earth  until  the  sun  is  dead  and  would  have  been  totally  ignorant  of 
its  composition  had  not  the  spectroscope  been  studied  out.  Mass, 
volume  and  density  do  not  give  any  indication  of  wrhat  the  mass 
is  composed.  The  energy  must  be  analyzed  and  waves  to  be  ex- 
amined by  themselves  must  be  separated  from  all  the  others  and 
this  is  done  by  prism  or  grating. 

COMPARISON. 

The  comparison  of  energy  from  the  sun  with  that  of  terres- 
trial substances  when  oscillating  under  the  action  of  heat,  is  per- 
formed by  passing  waves  from  the  sun  and  substance  through  the 
slit  at  the  same  time  side  by  side.  The  bright  lines  from  some 
phase  of  matter  on  earth  will  then  fall  end  to  end  against  dark 
absorption  lines  from  the  sun  if  there  are  any. 

This  is  shown  in  cut  22,  where  waves  from  some  incan- 
descent metal  is  passed  through  the  slit,  and  they  will  form  a 
spetcrum.  To  the  right  of  the  slit  at  5  in  cut  15,  and  at  5  in  cut  22 
is  a  small  right-angled  prism,  so  that  light  entering  a  side  is  re- 
flected at  right  angles  from  the  hypotenuse  as  shown  in  cut  22, 


RADIANT     ENERGY. 


67 


REVERSAL    IN    THE    SUN. 

Two  arc  light  carbons  are  shown  with  a  piece  of  metal  in  the 
crater  of  the  positive.  If  the  metal  vibrates  at  8  rates,  then  as 
soon  as  the  current  is  turned  on,  figure  I,  cut  22,  will  be  seen  on 
the  grating  in  the  upper  half  of  the  slit.  If  now  sunlight  is  pro- 
jected through  the  lower  half,  the  grating  will,  show  figure  2. 
There  are  8  reversals,  and  the  ends  of  both  sets  of  lines  coincide. 
It  is  at  once  inferred  that  the  same  metal  is  incandescent  in 
both  the  sun  and  arc. 

The  terminals  of  an  induction  coil  may  be  substituted  for 
the  arc,  in  which  case  the  heat  of  the  disruptive  discharge  vapor- 


DIRECT    SPECTRUM 


METAL 
SOLAR 


REVERSED  SPECTfturt 


tARBGHS, 


COLUMAIOR. 

Cut  22.     Light  from  Sun  and  Vaporized  Metals  compared. 

izes  the  metal,  or  low  metals  may  be  turned  to  gas  in  a  Bunsen  or 
alcohol  flame.  In  all  these  cases,  however,  the  differing  sets  of 
bright  lines  (one  set  for  each  metal)  will  come  opposite  a  set  of 
black  lines,  if  the  metal  in  question  is  reversed  in  the  sun. 

These  tests  have  been  made  by  skilled  spectroscopists  in  all 
parts  of  the  world,  and  the  results  have  been  subjected  to  the 
mathematical  theory  of  probabilities,  when  it  is  found  that 
the  chances  of  the  metal  existing  in  the  sun  are  as  three  trillion 
to  one. 

From  the  preceding  notes  it  is  known  that  black  lines  are 
caused  by  absorption;  for  take  the  metal  out  of  the  crater  and 


68  RADIANT     ENERGY. 

place  it  in  a  Bunsen  flame,  between  the  arc  and  slit,  as  shown  by 
the  dotted  lines  in  cut  19,  then  the  white  light  of  the  arc  will  pass 
through  the  dim  flame,  all,  except  the  eight  rates,  set  up  in  the 
flame.  Figure  I  will  be  filled  with  every  color  except  the  eight  lines, 
which  will  now  turn  black.  Thus  absorption  can  be  produced  in 
the  laboratory  corresponding  exactly  with  that  taking  place 
around  the  sun.  It  is  clear,  therefore,  since  selective  absorption 
is  produced  by  oscillating  gases  only,  that  there  must  be  vi- 
brating gases  between  the  sun  and  earth  as  well  as  between  the 
arc  and  slit. 

These  gases  constitute  that  wonderful  thing,  the  atmosphere 
of  the  sun.  The  air  there  is  made  up  of  gaseous  metals.  If  there 
are  other  modes  of  matter  in  the  sun,  they  are  in  a  state  of  disso- 
ciation, so  they  cannot  vibrate  in  rates  that  will  form  a  spectrum 
— at  least  in  the  visible  portion — or  are  obscured  by  the  profusion 
of  metallic  vapors  on  the  sun. 

Dissociation  is  Lockyer's  theory,  and  seems  to  point  to  the 
conclusion  that  there  exists  but  one  kind  of  matter.  The  sun 
then  contains  the  same  kinds  of  metals  at  least  that  make  up  the 
metallic  store  on  earth.  And  incredible  quantities  of  hydrogen, 
and  helium  also. 

Professor  Charles  A.  Young,  General  Astronomy,,  p.  215, 
Revised  Edition,  says  that  the  following  elements  are  known  to 
exist  in  the  sun. 

Iron,  Calcium,  Magnesium,  Erbium, 

Nickel,  Ccandium,  Sodium,  Zinc, 

Titanium,  Helium,  ,  Silicon,  Copper, 

Manganese,  Neodymium,  Hydrogen,  Silver, 


Chromium, 

Lanthanum, 

Strontium, 

Germanium 

Cobalt, 

Yttrium, 

Barium, 

Glucinum, 

Carbon, 

Niobium, 

Aluminum, 

Tin, 

Vanadium, 

Molybdinum, 

Cadmium, 

Lead, 

Zirconium, 

Palladium, 

Rhodium, 

Potassium. 

RADIANT     ENERGY.  69 

There  is  yet  a  question  as  to  the  existence  of  oxygen  in  the 
sun,  while  chlorine,  nitrogen,  bromine,  iodine,  etc.,  appear  to  be 
missing — or  if  present,  hidden  in  a  multitude  of  other  incan- 
descent vapors. 

But  the  vast  work  has  only  started,  for  there  are  large  num- 
bers of  absorption  lines  not  yet  identified  with  matter  on  earth. 

The  solar  atmosphere  is  complex  ;  but  not  disconcerted,  how- 
ever, with  the  great  task,  men  are  now  attacking  the  problem 
with  renewed  energy. 


7o  RADIANT     ENERGY. 


X. 

SOLAR    vSPECTROSCOPE. 

"As  one  sun  illumines  the  whole  world,  so  does  the  one  spirit  illumine 
the  whole  of  matter.  O !  Bharata."— Hindu  Bhagavad-Gita,  Ch.  XIII. 

Not  only  does  the  spectroscope  reveal  the  constituent  types 
of  matter  in  the  sun,  but  their  conditions  also.  The  sun  is  a 
mighty  globe  whose  surface  and  regions  above  are  in  a  state  of 
excessive  turbulence,  upheaval  and  unrest.  The  most  appalling 
explosions  of  pent-up  gases,  heated  to  temperatures  far  higher 
than  known  on  earth,  continually  occur.  Terrific  cyclones  and  hur- 
ricanes rend  the  sea  of  incandescent  vapors,  and  hot  metallic  winds 
blow  with  the  most  incredible  fury.  In  the  ninth  paper  it  was 
shown  how  the  spectroscope  tells  the  composition  of  solar  gases, 
by  means  of  readings  of  absorption  lines,  the  entire  story  being 
told  by  short  thick  and  thin  black  lines.  These  and  the  adjacent 
colors  are  all  that  can  be  seen  in  a  spectroscope  as  ordinarily  ar- 
ranged in  the  laboratory.  But  the  sun  itself  cannot  be  seen  in 
this  manner;  for  the  mirror  of  the  heliostat  does  not  magnify,  or 
if  a  lens  is  interposed  between  the  mirror  and  slit  it  merely  serves 
to  make,  a  small  image  of  the  sun  on  slit  plate. 

But  now  a  giant  lens  must  be  placed  between  the  sun  and  slit, 
and  the  heliostat  removed.  In  short,  the  spectroscope  must  be 
transformed  into  a  telespectroscope ;  that  is,  be  attached  to  the 
eye  end  of  the  great  telescope  in  the  dome  of  the  observatory,  the 
physical  laboratory  being  closed. 


RADIANT     BN ERG  Y.  77 

The  new  apparatus — the  telespectroscope,  is  shown  in  cut  23, 
where  the  spectroscope  so  far  treated  in  these  notes  is  seen  fas- 
tened to  the  end  of  the  sixteen-inch  telescope,  the  extreme  lower 


Cut  23.     Telespectrograph  in  the  L,owe  Observatory. 


end  of  which  appears.  The  great  lenses  are  in  the  other  end 
of  the  steel  tube  and  are  twenty-two  feet  higher  in  the  top  of 
the  dome  and  pointed  straight  toward  the  sun. 


RADIANT     ENERGY. 


Cut  24.     Fig.  14  L,ens  and  Tube  for  Projecting  Solar  Image  on  Slit; 
Fig.  15.     Slit  for  Solar  Spectroscopy  and  Vernier. 


The  slit  for  sun  work  is  shown  in  cut  24,  figure  15,  where  the 
slit  is  opened  hundreds  of  times  wider  than  when  in  use,  for  if 
narrow  it  would  be  invisible  in  cut.  The  movable  arm  and  vernier 
upon  which  the  figure  15  appears,  slides  around  the  ruled  circum- 
ference and  reads  the  position  angle  of  any  object  that  may  be 
seen  on  the  apparent  edge  of  the  sun.  These  angles  are  read 
from  the  North  Pole  of  the  sun  and  serve  for  future  reference 
in  making  daily  record  of  solar  phenomena.  It  also  rotates  a  tube 
behind  the  open  slit.  This  tube  contains  a  prism  seen  back  down 
on  the  table  to  the  left  of  the  solar  slit  and  circles,  which  makes 
the  image  of  the  sun  appear  to  revolve  around  the  axis  of  collima- 
tion  of  the  telescope.  Thus  the  entire  periphery  of  the  sun  can 
be  brought  rapidly  into  view. 

The  vertical  brass  bar  containing  the  slit  also  has  a  vernier  on 
the  opposite  side  of  the  circular  plate,  by  means  of  which  the 
position  of  the  slit  on  the  edge  of  the  sun  can  be  read.  The 
prism  inverts  everything.  Looking  through  the  slit  and  prism 


RADIANT     ENERGY 


73 


at  a  distant  house,  the  chimney  appears  all  right,  but  if  the  cross- 
bar and  tube  with  its  prism  be  turned,  the  chimney  will  point  to 
the  center  of  the  earth  and  to  the  sky,  alternately.  When  the 
great  object-glasses  of  the  telescope  are  gazing  at  the  sun  they 
form  an  exceedingly  brilliant  image  of  the  sun  at  their  focal 
plane,  at  i,  cut  23.  This  image  is  two  inches  in  diameter,  and 
the  edge  is  allowed  to  fall  on  the  narrow  slit,  now  closed  down 
to  a  width  of  i-ioooth  of  an  inch. 


Cut  '2ii.    Images  of  Sun  and  Slits. 

This  is  made  clear  in  cut  25,  where  a  front  view  of  the  top 
of  the  slit  end  of  the  collimator,  figure  I,  cut  23,  is  shown. 
In  figure  i,  cut  25,  the  slit  is  tangental  to  the  solar  image,  and  in 
figure  2,  radial,  the  light  enters  the  slit  and  falls  on  the  grating 
in  the  circular  box  at  2,  cut  23.  Here  the  light  is  diffracted  into 
a  long  brilliant  spectrum.  It  is  the  spectrum  of  the  sun.  It  is 
reflected  by  the  grating  to  the  spectro-camera  at  3.  where  it  is 
graphed  and  filed  away  for  future  study  and  comparison  with 
later  graphs.  Or  by  taking  off  the  plateholder,  an  eye-piece  can 
be  attached  for  viewing  solar  explosions  directly,  for  an  eye  (at 
the  eyepiece)  is  liable  at  any  time  to  see  colossal  explosions  hurl- 
ing white  hot  matter  to  vast  heights  with  terrific  velocity. 


74- 


R  AD  I  ANT     ENERGY. 


They  are  of  all  shapes  and  sizes,  a  few  types  being  shown  in 
cuts  26,  27  and  28.  The  lowest  in  any  of  the  figures  is  25,000  miles 
high  and  the  highest  shown  is  145,000  miles.  The  three  black  dots 


Cut  2f>.     Edge  of  Sun  Showing  Explosions.      The  Dot  is  the  Earth's  Exact  Size. 


in  26,  27  and  28,  represent  the  size  of  the  earth  in  compar- 
ison. In  cut  26  is  seen  a  porion  of  the  sun  with  six  spots,  and  the 
small  dot  is  also  the  size  of  our  earth  in  proportion  to  the  sun, 
explosions  and  spots.  Sun  spots  have  been  measured  whose  area 
was  32  times  that  of  a  section  of  the  earth,  so  32  worlds  like 
the  earth  could  tumble  in  side  by  side  with  room  to  spare.  The 
tele-spectroscope  therefore  renders  the  prominences  visible  and 


RADIANT     ENERGY. 


75 


of  Sun  Showing   Explosive  Prominences,  and  Relative  Size  of  the  Earth. 


tells  what  they  are  made  of  when  the  telescope  alone  could  not  do 
either.  The  philosophy  of  enabling  the  eye  to  see  the  protuber- 
ances is  that  the  grating  displaces  the  mixed  white  light  of  the 
atmosphere  of  the  earth.  All  know  that  the  sky  round  about 
the  sun  is  white,  due  to  diffusion  of  light  by  dust  and  aqueous 
vapor  in  the  air.  But  the  spectroscope  draws  this  white  into  a 
long  band  of  colors,  weakens  the  glow  and  intensity  of  radia- 


7<5 


BN  BRGY. 


tion.  This  is  because  the  light  is  white.  But  an  explosion  on  the 
sun  may  be  red,  each  set  of  waves  being  of  the  same  length. 
They  therefore  cannot  be  dispersed  farther;  images  of  the  slit  of 
any  object  whose  light  enters  it  will  be  separated  by  wide  dis- 
tances, but  their  brilliancy  will  not  be  lessened.  An  important 
result  follows :  They  can  be  seen  bright  on  a  dim  background. 
This  is  a  great  achievement  in  solar  work,  for  before  this  dis- 
covery astronomers  had  to  wait  until  a  total  eclipse  of  the  sun 


EARTH 

Cut  27A.     Explosions  on  Sun  ;  Also  a  Few  Sun  Spots  in  Comparison  With  the  Earth. 

occurred.  In  that  case,  the  moon  cut  off  the  sun,  but  left  the 
prominences  in  view  for  a  very  short  time.  Thanks  to  Lockyer 
and  Janssen,  these  wonderful  objects  on  the  sun  can  be  seen  in 
full  daylight.  In  cut  25,  figure  i,  the  slit  being  on  a  tangent  to 
the  sun's  image,  happens  to  include  three  explosions.  They  can 
be  either  analyzed  or  photographed.  Figure  2  shows  slit  radial, 
it  is  not  wide  enough  to  take  in  more  than  one  upheaval.  By 
rotating  the  arm  15  in  cut  24  the  entire  circumference  of  the 
sun  may  be  brought  before  the  slit  in  a  short  time,  and  every 
outburst  photographed.  And  men  are  making  perpetual  graphs 
of  the  sun,  a  continuous  record  for  coming  generations. 


RADIANT     ENERGY. 


77 


285 


Cut  28.     Explosions  on  the  Sun  and  Comparative  Size  of  Our  Earth. 

The  sun  cannot  make  an  upheaval  without  being  instantly 
photographed  somewhere  on  the  earth,  the  imperturbable  eye  of 
man  is  ever  on  the  sun,  for  when  it  is  setting  at  one  place  it  is 
rising,  or  is  at  meridian  altitude,  at  some  other.  The  sun  is 
now  writing  its  own  history,  and  it  is  a  most  interesting  diary. 

It  is  thought  that  a  graph  taken  now  and  one  ten  thousand 
years  hence  may  show  changes  in  the  constitution  of  the  solar 
mass,  and  that  men  by  that  time  will  have  accurate  knowledge 
concerning  that  stupendous  star,  the  sun. 


78  RADIANT     ENERGY. 


XL 
SPECTROSCOPY  OF  THE  SUN. 

"First  the  world  was  void, 
The  first  light  was  A  urn ; 
Thence  the  alphabet. 
The  seeds  of  the  universe!" 

— Primeval   Aryan   Literature,    Hodgson's    Trans.      Royal   Asiatic    Society, 
II,    332. 

Since  the  continued  existence  of  the  human  species  on  earth 
depends  entirely  on  the  radiant  energy  sent  out  by  the  sun,  this 
splendid  star  must  naturally  be  the  subject  of  admiration  and 
solicitude,  now  as  well  as  in  prehistoric  times.  The  vast  field 
of  research  and  exploration  has  scarcely  more  than  been  entered. 
The  combined  energies  of  man  must  be  centered  on  the  hercu- 
lean work  of  taking  energy  out  of  space  and  chain  it  to  his 
servitude.  Men  pay  for  power  now ;  it  should  be  free. 

All  problems  so  far  presented  to  men  for  solution  fall  into 
insignificance  in  presence  of  the  mighty  problem  of  the  ages — how 
change  the  lengths  of  waves  from  the  sun  and  make  them  fit 
for  human  use  ?  The  question  how  the  spectroscope  makes  the 
solar  explosions  visible  is  important  and  needs  further  study. 

In  cut  29,  figure  i,  is  shown  a  slit  filled  with  white  light.  In 
figure  2  is  the  same  slit  magnified.  It  is  clear  that  if  no  additional 
quantity  of  light  has  entered,  the  band  will  be  much  weakened 


RADIANT     ENERGY. 


79 


in  brilliancy  after  being  spread  over  so  much  greater  area.  And 
the  prism  or  grating  would  spread  it  over  the  entire  belt  if  the 
light  were  white,  but  not  widen  it  at  all  if  the  slit  contained 
red  or  blue  or  any  other  homogeneous  waves.  This  is  because 
white  light  contains  waves  of  every  degree  of  refrangibility — 
capability  of  being  bent  aside — and  homogeneous  light  only  one 
degree.  This  is  the  secret  that  renders  prominences  on  the  sun 
visible  without  an  eclipse. 


VI  B< 

i  Y  0 

R 

V    I    B     G     Y     0 


Cut  2! I.     Kig.   1,  Slit.     Fig.  '2,  Slit  Magnified.     Fig.  3,  Slit  with   One    1  xplosioi 
in  the  Red  Knd  of  the  Solar  Spectrum. 


Cut  29,  figure  3,  represents  a  wide  slit,  with  the  dim  out- 
lines of  an  eruptive  prominence  on  the  edge  of  the  sun,  invisi- 
ble to  the  eye  or  to  a  low-power  spectroscope,  for  the  white 
light  is  as  bright  as  whatever  may  be  the  color  of  the  cast-up 
matter.  In  figure  4,  the  wide  slit  is  magnified  still  wider  by  a 
high-power  spectroscope,  its  white  light  widely  dispersed  and 
greatly  weakened,  while  if  the  explosion  is  of  any  homogeneous 
color — say  red — its  light  is  not  dispersed  and  is  not  fainter,  it 
is  visible  against  the  dim  spectrum,  due  to  the  dispersed  white 
light  as  a  background,  and  appears  in  the  place  of  red. 


8o  RADIANT     ENERGY. 

WIDE  DISPERSION. 

The  process  of  being  rid  of  the  white  light  diffused  in  the 
earth's  atmosphere  is  shown  in  cut  30. 

The  prismatic  telespectroscope  in  cut  30,  takes  the  place 
of  the  Lowe  grating  telespectroscope  on  the  end  of  the  great 
telescope,  as  shown  in  cut  23,  Chapter  X.  Figure  I,  cut  30,  is  over 
the  slit  in  the  collimator  tube,  the  screw  for  opening  and  closing 


Cut  30.     Prismatic  Telespectroscope. 

the  slit  being  to  the  left  of  (i).  The  light  from  the  edge  of  the 
sun  comes  through  it  and  falls  on  the  lower  half  of  the  first 
prism  in  the  train.  This  disperses  the  light  somewhat  and  projects 
it  against  the  lower  half  of  the  next,  and  so  on  to  the  terminal 
prism,  marked  (2),  upon  whose  hypotenuse  falls  the  spectrum. 
This  reflects  it  without  change  through  the  top  half  of  the  first 
prism,  and  on  through  the  tops  of  all  until  it  emerges  from  the 
last  and  enters  the  open  tube  (3)  as  a  beautiful  spectrum.  It 
encounters  a  rectangular  prism  in  the  brass  box  (4),  which  re- 
flects it  up  to  the  eye-piece  (5),  through  the  micrometer  (6). 

An  eye  placed  at  (5)  may  at  any  time  during  the  day  see  an 
explosion  as  shown  in  cut  31,  figure  I,  for  instance,  where  quite 
a  number  of  ordinary  prominences  are  shown,  giving  no  indica- 
tion of  the  mighty  upheaval  soon  to  occur. 


RADIANT     ENERGY 


81 


Fio.  49. 


THE 
EARTH 


THE 
EARTH 


AS   SEEN    AT   8.30   P.  M. 

100,000  miles  to  tfie  inch. 

Cut.  31.     Solar  Explosions;    Figs.  1,  2,  and  3  Show  the  Great  Rapidity 
of  These  Turbulent  Masses. 


Figure  i  is  as  seen  by  Professor  Charles  A.  Young  of 
Princeton,  N.  J.,  College,  at  2:15  p.  m.,  July  25,  1872.  Figure 
2  is  at  2  145  p.  m.,  30  minutes  later,  and  3  is  the  same  at  3  130, 
after  an  interval  of  45  minutes.  The  scale  is  100,000  miles  to 
the  inch,  and  the  earth  is  shown  in  exact  size  to  the  left,  just 
above  the  figure  2.  The  height  of  the  explosion  at  2  is  125,000 
miles,  the  vertical  ascent  being  100,000  miles  in  30  minutes. 
When  it  reached  this  altitude  it  seems  to  have  been  caught  by 


82  RADIANT     ENERGY. 

a  mighty  wind  of  hot  metallic  vapor  and  bent  over  to  the  left 
at  almost  right  angles.  These  outbursts  are  classed  as  "the 
quiescent,  cloud-formed,  or  hydrogenous,  and  the  eruptive,  or 
metallic/'  Young,  Seechi,  etc. 

The  quiescent  are  composed  mostly  of  the  light  gas  hydro- 
gen, but  the  eruptive  look  like  jets,  spikes  and  projecting  horns. 
They  change  form  rapidly,  and  are  made  of  such  metals  as  mag- 
nesium, barium,  sodium,  iron  and  titanium  and  others  at  terrific 
heat.  Several  spikes  and  jets  are  shown  in  cut  31,  and  also  the 
dimensions  of  the  earth  to  the  right  of  the  jets.  The  highest 
prominence,  accurately  measured,  reached  a  height  of  309,000 
miles.  A.  P.  JL,  October,  1901,  page  213.  The  explosive  promi- 
nences at  times  are  so  intensely  brilliant  that  they  can  be  seen  on 
the  disc  of  the  sun  far  away  from  the  edge,  being  much  brighter 
than  the  solar  surface,  which  in  turn  is  many  times  brighter  than 
the  light  of  the  most  powerful  electric  arc  yet  produced.  Their 
velocities  of  ascent  range  from  50,  75,  100,  150,  .and  a  few  have 
been  measured  with  the  incredible  speed  of  250  miles  per  second. 
AYith  what  terrific  force  they  were  shot  forth  from  the  sun.  Per- 
haps at  the  instant  of  outburst  the  metals  were  in  gaseous  form 
so  dense  as  to  be  almost  liquid.  Cyclones  twist  up  white  hot 
matter  to  great  heights,  and  in  some  cases  the  tops  of  these 
expand  into  thin  clouds  and  remain  up  for  several  days  floating 
upon  the  upper  layers  of  denser  gases  beneath. 

Professor  W.  W.  Campbell  of  the  Lick  Observatory,  in  his 
lecture  to  the  Southern  California  Academy  of  Sciences  in  Los 
Angeles,  on  March  nth,  1902,  presented  a  series  of  photographs 
showing  that  some  of  these  outbursts  are  intimately  related  to 
sun  spots.  The  mystery  of  the  sun  is  the  vast  quantity  of  hydro- 
gen extending  entirely  around  it  in  sheets  or  layers,  and  also 
being  incessantly  hurled  forth  from  below  the  apparent  surface 
with  a  force  thousands  of  times  greater  than  that  of  hissing  steam 
from  a  high-pressure  boiler. 


RADIANT     BNBRGY.  83 

In  cut  30,  figure  6,  is  shown  that  powerful  instrument,  the 
spectro-micrometer.  It  measures  every  object  in  the  field  of 
view  with  extreme  accuracy.  The  screw  carrying  the  wires  is 
shown  to  the  left,  close  to  the  6.  The  value  of  one  turn  of  this 
screw  in  seconds  of  arc  must  be  found  by  astronomical  methods. 
When  this  is  determined  the  wires  can  be  removed  up  so 
as  to  just  include  an  explosion  or  spot  between;  then. the  screw 
may  be  turned  until  both  wires  coincide  and  appear  as  one.  The 
number  of  turns  multiplied  by  the  value  of  one  turn  in  miles  or 
kilometers,  gives  the  height  or  diameter.  The  angular  diameter 
of  the  sun  is  1,924  seconds  of  arc;  and  its  distance  is  93,000,000 
miles.  From  an  elementary  rule  in  trigonometry  it  is  known  that 
one  second  is  450  miles  on  the  solar  disc.  If  a  prominence  ex- 
tends to  the  height  of  five  minutes,  or  300  seconds,  its  altitude  is 
135,000  miles. 

Measures  are  recorded  of  all  these  that  are  worthy  of  record. 
But  of  all  records  yet  devised,  those  made  by  the  photograph  are 
the  most  accurate.  This  leads  to  that  high  branch  of  research — 
solar  photography. 


84-  RADIANT     ENERGY. 


XII. 
RADIANT  ENERGY  AND  ITS  FIXATION. 

O  Thou  of  whom  all  is  the  manifestation, 

Thy    nature    is    the    spring    of    thy    being: 

Whatever  is,  is  thou ; 

We   are   all   billows    in   the   ocean   of   thy   being; 

We  are  a  small  compass 

Of  thy  manifested  nature 

—From  Dabistan,  Vedantic  Phil.,  Hindu. 

This  paper  might  more  properly  be  called  radiant  energy  and 
its  fixation.  For  now  radiant  and  oscillating  energy  is  to  meet 
cessation,  the  waves  are  to  do  work  on  particles  of  silver,  leave 
their  records  and  come  to  rest.  The  sun  must  do  writing  and 
imprint  graphs  of  its  daily  work,  ceaseless  turbulence  and  up- 
heaval. 

The  water  at  the  foot  of  Niagara  is  not  more  turbulent  and 
not  tossed  and  torn  into  more  fantastic  shapes  than  is  the  seething 
surface  of  the  sun.  But  how  shall  these  fleeting  forms  be  photo- 
graphed, and  by  what  possible  means  can  an  explosion  hurling 
up  white  hot  jets  40,000  miles  wide  and  200,000  high,  with  the 
terrific  speed  of  200  miles  per  second  be  instantly  portrayed  on  a 
sensitive  plate  so  as  to  appear  at  rest,  like  the  spokes  of  the 
driving  wheel  of  a  locomotive  moving  a  mile  a  minute  ?  And  the 
heat — will  not  the  great  heat  of  the  sun  destroy  plates  and  pre- 
vent light  from  making  record  ?  These  were  the  problems  that 
were  encountered  by  astronomers  from  the  year  1850.  Not  only 
must  the  prominences  be  made  to  record  their  forms,  but  spots, 
facul?e,  granulations,  filaments,  solar  clouds  and  corona  had  to 
be  made  to  appear  on  the  films;  but  of  far  more  importance,  the 


RADIANT     ENERGY.  85 

solar  spectrum  also  was  required  to  make  imprint,  or  little  could 
be  learned  of  the  constitution  and  structure  of  that  majestic 
object — the  sun.  And  then  came  workers  who  knew  no  rest, 
whose  labors  were  more  arduous  than  those  of  Hugo's  ''Toilers 
of  the  Sea." 

In  a  preceding  paper  a  cut  was  inserted  showing  three 
colossal  engines  at  work  for  the  enlightenment  of  man,  the  cal- 
culus, lens  and  grating.  To  these  must  now  be  added  a  fourth, 
the  gelatine  bromide  plate.  It  brought  work,  toil  unknown  in 
intensity  outside  an  astronomical  observatory.  The  sensitive 
plate  now  takes  rank  with  the  discoveries  of  the  ages — like  the 
Copernican  system,  the  laws  of  Kepler,  the  law  of  gravity,  the 
invention  of  the  telescope  and  spectroscope,  the  multiplex  tele- 
graph, induced  electricity,  the  dynamo,  the  wireless  telegraph 
and  telephone,  Hertzian  and  Roentgen  waves,  the  obscure  radia- 
tions of  the  Curies,  liquid  hydrogen  and  slow  but  sure  approach 
to  the  end,  the  absolute  zero. 

Those  who  reared  the  pyramid  of  Sulphis,  dug  the  Suez 
Canal,  tunneled  mountains,  made  ocean  steamers,  laid  the  Atlantic 
cable,  bridged  Niagara,  laid  the  railways  of  the  earth  and  set 
up  the  dynamo,  did.no  more  remarkable  work  than  the  toilers 
who,  from  1834  to  1902,  wrought,  day  and  night,  to  bring 
astronomical  photography  to  its  present  high  estate — to  the  full- 
ness of  majestic  science.  The  plate  is  displacing  men  from  the 
eye-end  of  the  telescope,  the  human  body,  nerves,  brain  and  eye, 
with  all  their  forms  of  personal  idiosyncrasy,  imperfections, 
limitations  and  errors,  must  go ;  the  plate  makes  no  mistake.  Not 
less  remarkable  were  researches  on  the  application  of  photography 
to  astronomy  than  were  those  so  long  and  persistently  made  to 
find  the  cause  of  the  Fraunhofer  lines. 

The  first  attempt  to  photograph  the  sun,  or  rather  its  spec- 
trum, was  made  by  Professor  J.  W.  Draper,  in  1834.  He  had 
merely  a  sheet  of  paper  roughly  coated  with  silver  bromide.  He 


86  RADIANT     ENERGY. 

failed,  but  the  effort  was  a  turning  point  in  human  advance. 
He  took  a  small  daguerreotype  of  the  moon  in  1840.  M.  Da- 
guerre  having  discovered  his  process  on  August  13,  1839.  Dra- 
per, in  1842,  and  Becquerel,  both  made  types  of  the  moon,  and 
in  1843,  made  a  graph  of  a  rough  diffraction  spectrum. 

Foucault  and  Fizeau,  on  April  2,  1845,  actually  produced  a 
daguerreotype  of  the  sun.  Then  came  Bond,  in  the  now  historic 
Harvard  College  Observatory,  and  took  graphs  of  the  moon  in 
1850,  and  copies  were  exhibited  in  London  on  May  9th  of  that 
year.  On  July  17,  1850,  Bond  and  Whipple  took  the  first  photo- 
graph of  a  star,  the  star  Alpha  Lyne. 

In  1851  Busch  took  the  first  graph  of  a  solar  eclipse.  All 
these  were  daguerreotypes.  Then  came  the  collodion  process, 
and  De  la  Rue,  in  1852,  took  graphs  of  the  moon  by  means  of 
wet  plates.  On  June  9,  1854,  Hartnup  presented  ten  collodion 
graphs  of  the  moon  to  the  Royal  Art  Society  in  London. 

April  24,  1854,  was  a  prophetic  day,  for  Sir  John  Herschel 
recommended  that  daily  photographs  of  sun  spots  be  made. 
From  1857  to  1863  Professor  Henry  Draper  made  many  collodion 
graphs,  '1,500,  of  the  moon,  with  ever  increasing  definition.  In 
1857,  Bond,  with  more  sensitive  collodion  plates,  photographed 
stars,  even  to  the  sixth  magnitude.  He  began  a  historic  move- 
ment, for  he  measured  the  distances  between  the  minute  dots,  the 
stellar  images,  giving  rise  to  accurate  determinations  of  star 
motions,  if  any  are  shown  on  later  graphs.  Rapid  advance  was 
made  from  1857  to  1860  by  many  physicists,  most  notable  of  all 
being  De  la  Rue,  Bond  and  Pritchard.  Rutherford  began  his 
great  work  in  1858,  and  made  research  on  lenses  and  mirrors. 
July  18,  1860,  is  memorable,  for  De  la  Rue  and  Seechi  both 
secured  graphs  of  the  total  solar  eclipse  of  that  date  in  Spain, 
and  proved  that  the  prominences  were  actually  on  the  sun  and  not 
an  optical  illusion  on  the  edge  of  the  moon,  for  the  advancing 
edge  of  the  moon  covered  and  uncovered  the  scarlet  jets  and 


R.ADI  ANT     ENERGY.,  87 

heaps.  On  February  2/th  and  March  3d,  Huggins  obtained  a 
graph  of  the  spectrum  of  the  star  Sirius.  It  was  not  until  1865 
that  Rutherford  discarded  lenses  corrected  for  visual  waves  and 
made  objectives  corrected  for  those  waves  only  making  the  best 
action  on  salts  of  silver.  This  placed  modern  astronomical  pho- 
tography on  a  strictly  scientific  basis.  His  graphs  were  marvels 
of  definition  and  perfection.  On  November  28,  1870,  that  emi- 
nent American  astronomer,  Professor  Charles  A.  Young,  photo- 
graphed the  prominences  on  the  sun  without  an  eclipse.  In  1874 
photography  was  used  in  recording  the  positions  of  the  planet 
Venus  in  its  transit  across  the  solar  disc.  These  positions  are 
used  to  obtain  the  distance  of  the  earth  from  the  sun.  All  the 
graphs  so  far  taken  were  on  collodion  plates.  But  now  comes  a 
most  important  improvement — record  breaking  so  it  proved. 

DRY    PLATES. 

That  auspicious  year,  1876,  came,  and  with  it  gelatine  dry 
plates  sensitive  enough  for  astronomical  graphs.  Immense  impe- 
tus was  at  once  given  to  graphic  research,  for  these  plates 
could  be  exposed  for  hours,  on  faint  work,  all  night,  in  fact,  if  at 
work  on  stars  and  ncbulre.  The  gelatine  film  holds  the  particles 
of  silver  bromide  in  place  so  they  will  store  the  radiant  energy 
of  the  universe.  Now  storage  of  energy  is  the  highest  achieve- 
ment of  human  hands.  Huggins  soon  stored  energy  falling  on 
the  earth  from  the  star  Vega,  and  saw  on  his  plate  seven  strong 
absorption  lines.  On  July  20,  1877,  Draper  discovered  oxygen 
in  the  sun,  and  from  this  time  astrophysics  made  the  most  rapid 
progress  since  the  primeval  Aryans  watched  the  stars  from  the 
uplands  of  Central  Asia. 

Exceedingly  rapid  exposure  is  made  for  sun  work,  and 
extremely  slo\v  for  faint  star  graphs.  Photographs  may  be  taken 
hourly  of  the  prominences,  as  well  as  spots,  faculae,  or  the  entire 
disc. 


88 


RADIANT     ENERGY. 


Cut  32.    Solar  Prominences  ;  Mainly  Hydrogen  ;  Helium  and 
Gaseous  Metals  Also. 


Cut  33.    Spectra  of  Four  Suns  ;     Alpha  Orionis,  Beta  Pegasi,  Alpha  Lyn 
and  Our  Own  Sun  at  the  Bottom  of  Cut. 


RADIANT     ENERGY. 


S9 


Cut  32  reveals  a  number  of  forms  of  solar  explosions.  Their 
height  varies  from  20,000  to  160,000  miles,  the  lowest  shown 
being  about  three  times  the  diameter  of  the  earth  in  height.  These 
gigantic  outbursts  are  of  a  bright  red,  against  a  dull  red  back- 


Cut  34.    Total  Eclipse  of  Sun ;   Showing  Corona  ;    the  Black  Center  is  the  Moon. 

ground  in  the  spectroscope.     Their  composition  is  largely  hydro- 
gen. 

Cut  33  shows  spectra  of  four  suns,    Alpha    Orionis,   Beta 
Pegasi,  Alpha  Lyrae,  and  our  own  sun  being  at  the  bottom. 


QO  RADIANT     ENERGY. 

Cut  34  is  that  of  a  total  eclipse,  showing  the  black  body  of 
the  moon  in  front  of  the  sun,  cutting  off  its  light,  allowing  the 
explosive  prominences  to  appear  around  the  edges,  with  the  great 
streamers  of  the  corona  far  beyond.  This  photo  was  taken  with- 
out a  spectroscope,  as  no  dispersion  was  required. 


Cut  35.     Ordinary  Laboratory  Spectroscope. 


Cut  35  is  that  of  an  ordinary  Browning  spectroscope  used  in 
a  laboratory  for  making  analysis,  and  is  not  used  in  astronomical 
researches. 


RADIANT     ENERGY.  9i 


XIII. 

SOLAR   SPECTROGRAPHY. 

"His  radiance  is  undecaying."— Rig  Veda. 
"The  royal  sun  feedeth  all." — Sophocles  Oedipus  Tyrranus  660. 

This  has  now  become  an  important  branch  of  work  in  a 
modern  astrophysical  observatory. 

The  year  1877  was  also  auspicious,  for  Janssen  rose  up  and 
photographed  the  sun  with  clearness  of  detail  not  reached  before. 
His  graphs  were  one  foot  in  diameter,  and  displayed  intricate 
tracery  of  the  sun  with  sharp  definition.  Countless  tops  of  promi- 
nences appeared  on  his  plates,  all  over  the  solar  disc,  where  before 
the  sides  only  of  the  exploded  masses  on  the  limb  of  the  sun 
were  seen. 

His  solargraphs  show  granulations,  shaped  like  grains  of 
rice,  and  a  network  of  distorted  forms  of  white  hot  matter  below 
or  round  about.  The  solar  surface  is  mottled  and  looks  like  the 
elevations  and  depressions  of  very  coarse  and  rough  blotting 
paper,  as  seen  through  a  low  power  lens. 

Janssen  says :  "The  forms  generally  have  rounded  contours, 
but  some  are  rectilinear  and  others  polygonal,  and  in  the  intervals 
of  this  network  the  rice-grains  are  distributed,  the  granules  being 
half  obliterated,  drawn  out  and  confused."  Popular  Astronomy, 
Vol.  II,  312,  H.  C.  Russell. 

The  success  of  this  intensely  difficult  work  was  reached  by 


92  RADIANT     ENERGY. 

reducing  the  time  of  exposure  of  the  sensitive  plate  to  the 
i-3<DOOth  part  of  a  second.  The  evanescent,  rapidly  moving  and 
fleeting  tops  of  the  heated  jets  were  caught  on  his  plates  and  ren- 
dered motionless,  among  scenes  of  the  most  appalling  unrest  and 
explosive,  cyclonic  and  disruptive  activity. 


Cut  36.    JansserTs  Photograph  of  vSolar  Disc;     Showing  Granulations, 
or   Tops  of  Prominences  and  One  Spot. 


Cut  36  is  Janssen's  photograph  of  the  solar  disc  showing 
the  roughness  and  granules  supposed  to  be  the  crests  or  tops 
of  the  jets  and  prominences.  Two  spots  are  also  in  range  of  the 
camera. 

In  1878  Dr.  Henry  Draper  photographed  the  spectrum  of  the 
sun's  corona,  seen  at  the  total  eclipse,  and  showed  that  the 
corona  shines  by  reflected  light.  There  must  be  matter  near  the 
sun  to  reflect,  and  this  is  conceived  to  be  in  vast  banks  of  ex- 
ceedingly fine  cosmical  dust,  so  fine  as  almost  to  assume  the 
properties  of  a  gas,  for  comets  have  been  seen  to  tear  through  it 


RADIANT     ENERGY.  93 

with  the  terrific  speed  of  200  miles  per  second  without  retardation 
or  disruption. 

The  first  mention  of  this  wonderful  halo  round  about  the 
sun  is  by  Plutarch,  as  seen  at  the  total  solar  eclipse  March  20,  A. 
D.  71.  It  was  not  mentioned  again  in  the  literature  of  astronomy 
until  near  the  close  of  the  sixteenth  century;  since  when  it  has 
been  watched  and  studied  with  ever  increasing  interest  and  ac- 
curacy. 

It  is  well  to  make  close  study  of  the  sun,  for  it  is  merely 
a  small  star,  and  being  so  near  the  earth,  every  fact  gained  by 
comparatively  easy  means,  will  be  of  great  use  when  that  other 
branch,  stellar  spectrography  is  reached.  If  a  journey  from 
the  earth  to  the  sun  be  made,  the  first  matter  encountered  as 
the  sun  is  approached  will  be  the  solar  corona,  an  object  ex- 
tending in  gigantic  streamers  into  space  from  300,00x3  to  2,000,- 
ooo  or  more  miles.  It  is  a  luminous  body  and  is  truly  solar.  The 
diffused  light  of  the  earth's  atmosphere  makes  a  white  halo 
around  the  sun's  disc  totally  obscuring  this  crown  worn  by  the 
sun.  But  when  the  moon  cuts  off  the  sun's  fierce  light  at  times  of 
total  eclipses,  the  delicate  filaments  of  the  corona  are  seen  in 
magnificent  display.  It  is  made  up  of  long  bright  streamers 
and  at  times  darker  spaces  are  observed  between  them. 

The  intensity  of  coronal  light  is  about  three  times  that  of 
the  full  moon,  but  varies  at  different  eclipses,  and  while  intense 
near  the  sun,  it  rapidly  wanes  with  increasing  distance. 

The  corona  seems  to  be  made  up  of  three  portions.  There 
are  filamentary  streamers  and  bands  emanating  from  the  polar 
regions  of  the  sun,  and  these  are  almost  straight.  The  bands 
near  the  sun's  equator  and  close  to  the  surface  are  curved,  and  at 
some  eclipses  long  streamers  rise  high  above  these  in  the  equa- 
torial regions.  Slow  changes  in  the  form  of  the  corona  are  taking 
place,  but  no  rapid  displacements,  like  those  seen  in  the  jets  and 
prominences  below,  have  been  detected. 


W  RADIANT     ENERGY. 

In  the  eclipse  of  1893  the  corona  was  photographed  in 
Chile,  South  America,  and  two  and  one-half  hours  later  it  was 
also  graphed  in  Africa,  and  both  pictures  were  identical.  Yet, 
no  two  eclipses  present  the  same  forms.  The  changes  appear  to 
follow  the  eleven-year  spot  period.  At  the  times  of  sun  spot 
maxima  the  coronal  streamers  are  short,  brilliant  and  of  complex 
structure,  but  in  spot  minima,  the  corona  is  irregular,  with 
short  tufts  around  about  the  poles  of  the  sun ;  and  also  extremely 
long  streamers  reaching  distances  of  two  or  three  million  miles, 
along  the  plane  of  the  earth's  orbit.  The  streamers  look  some- 
what like  an  aurora  on  the  earth. 

Total  eclipses  during  a  hundred  years  afford  only  an  hour 
or  two  in  which  to  study  the  marvelous  object.  Spectroscopists 
are  always  busy  in  the  midst  of  an  eclipse;  in  fact  a  long  row 
of  spectroscopes  are  set  hundreds  of  miles  apart  on  the  earth's 
surface,  good  care  being  taken  to  have  all  the  observers  in  the 
center  of  the  line  of  totality.  The  coronal  light  projects  a  faint 
continuous  spectrum,  and  from  KirchhofFs  first  law7  it  is  known 
that  the  light  comes  from  incandescent  solids  or  liquids.  Pro- 
jected on  this  background  is  seen  a  bright  line  spectrum.  The 
second  law  of  spectroscopy  teaches  that  this  spectrum  is  cast 
by  light  from  glowing  gases. 

The  gas  most  plentiful  in  the  corona  is  hydrogen.  But  a 
most  mysterious  double  line  in  the  green  region  numbered  14/4 
is  also  observed.  One  of  these  lines  is  due  to  iron — that  is,  it 
coincides  end  to  end  with  an  absorption — black — line  in  the 
spectrum  of  the  sun's  surface  far  below. 

But  the  other  line  does  not  coincide  with  the  line  of  any 
mode  of  matter  yet  found  on  the  earth.  And  now  chemists  and 
spectroscopists  are  ransacking  everything  on  earth  to  find  it.  The 
eagerly  sought  substance  is  named  coronium — the  name  will  be 
all  ready  to  put  into  telegrams  that  will  be  flashed  to  every  ob- 
servatory in  the  world  by  the  fortunate  spectroscopist  finding  it. 


RADIANT     ENERGY.  95 

The  gas  helium  was  seen  casting  its  line  in  the  solar  spectrum 
for  years ;  and  the  earth  was  turned  bottom  side  up  to  find  it 
here,  and  it  was  actually  discovered  by  Ramsay  in  1895  in  the 
mineral  called  cleveite. 

An  exceedingly  refined  spectroscopic  observation  was  made 
by  Deslandres  which  proved  that  the  corona  revolves  with  the 
sun.  If  a  source  of  light  either  approaches  or  recedes  in  the  line 
of  sight,  the  spectroscope  at  once  detects  the  motion.  He  photo- 
graphed the  spectrum  of  the  portions  of  the  corona  on  opposite 


Cut  ;>7.     Total  Solar  Eclipse,  Showing  Lower  Portion  of  Corona. 

sides  of  the  sun  and  saw  that  the  tufts  and  streamers  on  the 
east  side  of  the  sun  were  moving  toward  the  earth,  while  those 
on  the  west  side  were  receding.  But  the  sun  also  revolves  from 
west  to  east. 

Cut  37  is  a  total  solar  eclipse  of  sun  showing  matter  hurled 
up  on  the  edge  of  disc. 


96 


RADIANT     UN  HRGY. 


Cut  38.    Trouvelot's  Total  Solar  Eclipse  ;  July  29,  1878. 

Cut  38  is  the  magnificent  drawing  made  by  Trouvelot  of  the 
great  corona  of  the  total  eclipse  of  July  29,  1878,  made  at  Creston. 
Wyoming.  The  polar  streamers  and  equatorial  extensions  are 
shown  in  detail,  also  the  glorious  corona  of  the  sun. 


RADIANT     ENERGY.  97 


XIV. 
SPECTRUM  ANALYSIS  OF  THE  SUN. 

"In  the  beginning  there  arose  the  source  of  golden  light." — Rig  Veda, 
Ch.  10-121,  B.  C.  1500,  Aryan  Scriptures. 

"From  darkness  lead  me  to  light." — From  "Brihad  Upanishad,"  Hindu 
Philosophical  Poem. 

Elaborate  study  of  the  sun's  surrounding  can  only  be  made 
at  times  of  complete  eclipse.  The  light  and  heat  from  the  disc  are 
so  intense  that  close  examination  of  the  photosphere  and  corona 
cannot  be  made  until  the  welcome  moon  comes  along  and  cuts  out 
the  sun,  leaving  the  external  banks  and  clouds  of  incandescent 
gases  in  plain  view.  It  must  be  ail  occasion  of  wonder  and  sur- 
prise to  many  to  see  the  civilized  nations  of  the  world,  as  well 
as  universities  and  observatories  send  costly  eclipse  expeditions 
to  remote  parts  of  the  earth  to  watch  the  extinction  of  the  sun, 
which  they  know  can  last  but  a  few  minutes. 

In  cut  39  is  shown  the  path  of  the  eclipse  of  January  21, 
1898.  The  black  line  from  Africa  through  India  to  Eastern 
Siberia  is  the  path  of  total  obscuration  of  the  sun.  Any  astron- 
omer to  see  the  splendid  and  impressive  spectacle  must  be  within 
this  track.  The  widest  possible  shadow  is  167  miles,  but  usually 
the  width  is  much  less.  The  mechanism  of  the  solar  system  is 
known  with  such  accuracy  that  the  exact  places  on  the  earth 
where  the  eclipse  will  be  total  is  computed  years  beforehand.  So, 


RADIANT     ENERGY. 


each  Government  knows  precisely  where  to  send  observing  parties. 
Sometimes  astronomers  pay  their  own  expenses,  and  at  others, 
some  generous  patron  of  science  foots  the  bill.  Many  parties  went 
to  India  in  1898  and  the  obesrvations  were  so  successful  that  this 
eclipse  is  selected  for  explanation  here. 

Among  the   triumphs   of  the   spectroscope   is   its  invaluable 


Cut  39.     Path  of  Solar  Eclipse,  Jan.  21,  1898. 

determinations  of  the  constitution  of  the  gases  round  about  the 
sun  which  cannot  be  studied  in  a  telescope  alone.  This  is  be- 
cause no  telescope  can  analyze  light.  At  the  instant  of  totality 
every  telespectroscope  is  set  on  the  sun  and  rapid  photographs 
are  taken.  Plates  are  exposed  and  changed  in  the  spectographs 
by  hands  trained  by  days  of  practice  and  drill,  so  that  the  human 
frame  becomes  an  instrument  of  mechanical  precision.  To  each 
observer  is  assigned  a  definite  thing  to  do  at  a  certain  absolute 
moment  of  time.  None  of  these  can  take  their  eyes  from  their 


RADIANT     ENERGY. 


99 


spectrographs,  telescopes,  polariscopes,  etc.,  so  a  man  is  stationed 
at  a  chonometer  to  announce  the  fleeting  seconds.  When  he  calls 
the  time,  each  human  machine  moves  in  a  carefully  prepared  pro- 
gramme. Since  the  invention  of  that  wonder  of  the  ages,  the 
dry  plate,  and  the  rise  of  that  vast  science,  spectro-photography, 
expeditions  are  sent  to  the  ends1  of  the  earth  to  secure  per- 
manent records — that  is,  photographs  of  all  phenomena  seen  at 


Cut  40. 


Professor  Campbell's  Eclipse  Outfit,  Jeur,  India. 

the  eclipse,  as  shown  in  the  telespectroscope.  This  is  an  instru- 
ment of  great  power  attached  to  the  telescope,  whose  objective 
collects  the  light  emanating  from  gases  near  the  sun  and  projects 
them  into  the  spectrograph.  This  analyzes  the  waves,  sorts  them 
out  according  to  their  rates  and  lengths,  and  spreads  them  upon 
the  plate,  to  make  graphs  to  be  stored  for  coming  generations. 
Complete  records  are  thus  made  of  every  eclipse,  unless  obscured 
by  clouds. 


/oo  RADIANT     ENERGY. 

The  graphs  of  the  Indian  eclipse  were  the  best  ever  se- 
cured to  that  time.  Everybody  went  armed  with  the  best  instru- 
ments known  to  science.  It  was  agreed  to  obtain  the  best  nega- 
tives possible  of  the  corona  and  prominences,  but  above  all  to 
record  the  "flash  spectra"  of  both  contacts.  Many  parties  went 
to  India. 

The  Lick  Observatory  sent  an  expedition  under  the  direc- 
tion of  Professor  W.  W.  Campbell,  and  cut  40  is  his  station  at 
Jeur.  The  great  inclined  tube  is  a  telescope  of  forty  feet  focal 
length.  Its  lower  or  photographic  end  is  lowered  into  a  pit 
eight  feet  deep,  where  the  object  glass  above  projects  an  image 
of  the  sun  five  inches  in  diameter  on  the  sensitive  plate,  in  its 
focal  plane.  Nothing  can  exceed  the  skill  required  to  mount 
all  these  instruments,  before  the  day  of  the  eclipse,  with  such 
accuracy  that  the  sun  will  come  exactly  in  front  of  the  ob- 
jective at  the  supreme  moment.  After  the  momentous  event  Pro- 
fessor Campbell  sent  this  telegram  to  the  Lick  Observatory: 

"The  most  satisfactory  photographs  of  the  corona  were  ob- 
tained with  the  three  different  telescopes.  One  set  with  a  tele- 
scope forty  feet  long,  and  two  other  sets  with  five-foot  and  three- 
foot  telescopes.  The  great  equatorial  extensions  of  the  corona, 
which  formed  such  a  conspicuous  feature  of  the  eclipse  of  Jan- 
uary, 1889,  has  again  been  photographed.  Also  satisfactorily 
photographed  the  changes  in  the  solar  spectrum  at  the  sun's 
edge  with  the  aid  of  one  of  the  spectroscopes." 

Professor  Burckhalter,  of  the  Chabot  Observatory,  was  also 
present  with  the  Pearson  telescope. 

THE   IXASH    SPECTRUM. 

The  most  consummate  skill  is  required  to  secure  a  spectrum 
of  the  reversing  layer.  The  highest  type  of  the  genius  of  man 
is  on  display  here.  He  must  have  every  instrument  ready  and 


RADIANT     ENERGY.  wi 

every  adjustment  made  with  accuracy  before  the  critical  time. 
The  flash  spectrum  must  be  secured  within  two  seconds,  or  the 
journey  of  10,000  miles  will  prove  a  failure.  Photographing 
the  flash  spectrum  is  one  of  the  chief  results  of  modern  research 
on  the  sun,  and  should  be  understood.  The  true  surface  of  the 
sun  is  doubtless  invisible  from  the  earth.  Its  condition  is  un- 
known, but,  since  the  entire  sun  is  only  41  per  cent  more  dense 
than  water,  the  density  must  be  greater  at  the  center  and  least  at 
the  surface.  The  sun  is  in  all  probability  made  of  liquid  gas  due 
to  its  own  pressure.  This  may  sound  anomalous,  but  compress 
hydrogen  under  a  piston  to  say  one-fiftieth  its  normal  volume, 
remove  the  pressure — the  gas  will  expand  and  the  piston  rise.  The 
sun  is  not  a  permanent  liquid,  like  water,  and  if  solar  gravity 
could  be  removed  the  sun  would  expand  to  planetary  distances  no 
doubt.  It  is  inferred  that  the  sun's  surface  is  a  liquid  gas  of  low 
density,  in  a  state  of  terrific  heat  and  intense  brilliancy.  Above 
this,  entirely  around  the  sun,  is  a  deep  layer,  or  envelope,  the 
photosphere,  and  this  is  what  is  seen  in  the  telescope. 


THE   CARBON    PHOTOSPHERE. 

Recent  researches  have  led  to  astounding  conclusions  as  to 
its  composition.  Perhaps  the  concept  of  Sir  Robert  Ball  is  the 
absolute  truth  on  this  important  subject;  for  man  lives  only  by 
radiance  from  the  photosphere.  It  is  now  known  that  carbon 
exists  in  the  sun.  This,  in  solid  form  on  earth,  appears  in 
diamonds,  charcoal,  coal  and  coke,  and  is  the  most  difficult  of 
all  known  substances  to  melt  or  make  liquid.  Its  specific  gravity 
in  gas  or  in  finely  divided  particles,  as  in  smoke,  is  low.  It 
easily  rises  through  the  earth's  atmosphere  against  gravity.  The 
appalling  heat  of  the  sun  is  able  to  turn  even  refractory  carbon 
to  liquid,  and  then  to  gas.  Its  gas  will  rise  through  the  dense 


I02  RADIANT     BNHRGY. 

metallic  vapors  surrounding  the  sun  into  cooler  regions,  condense 
into  liquid  drops,  or  possibly  into  solid  diamonds,  and  fall  and 
collide  near  the  solar  surface.  The  collisions  form  the  photo- 
sphere, therefore  the  photosphere  of  the  sun  is  literally  a  colossal 
storm  of  rain  and  hail  of  liquid  and  semi-solid  diamonds. 

Diamonds  are  not  stones — they  are  chemically  pure  carbon, 
and  will  unite  with  oxygen  without  residue.  And  this  is  the  lat- 
est conception  of  that  marvelous  thing — the  photosphere  of  the 
sun.  Metals  allowed  to  resist  electricity  are  instantly  vaporized, 
and  the  reason  why  carbon  is  used  in  arc  lights  and  incandescent 
bulbs  is  because  it  does  not  liquify.  The  brain  cannot  conceive  the 
brilliancy  of  the  white-hot  carbon  rain  in  the  sun's  photosphere, 
nor  imagine  the  degree  of  heat.  Other  refractory  substances,  as 
silicon  and  perhaps  some  metals,  rise  in  gas,  condense  and  fall ; 
but  none  fall  back  so  far  as  carbon  where  they  are  again  turned 
to  vapor,  so  the  layer  nearest  the  actual  solar  surface  is  pure 
carbon — a  thick  shell  of  liquid  diamond,  with  here  and  there 
a  white-hot  semi-solid  gem. 

But  above  this,  entirely  around  the  sun  are  piled  up  colossal 
heaps  and  tumbling  clouds  of  cooler  gases,  the  chromosphere. 
What  follows  ? 

From  Kirchhoff's  first  law  (second  paper)  ;  "All  solids, 
liquids  and  gases  under  great  pressure  project  continuous  spec- 
tra." The  spectrum  of  the  photosphere  is  continuous.  By  Law 
III,  (eighth  paper),  "All  modes  of  matter  when  vibrating  at 
their  own  rates  absorb  the  same  waves  they  emit."  Thus  the 
cooler  layers  of  gases  above  the  carbon  envelope,  yet  hot  enough 
to  vibrate  at  their  own  rate,  absorb,  quench  and  destroy  the  motion 
of  all  waves  sent  up  from  below,  and  these  cannot  reach  the 
earth.  All  waves  so  destroyed  leave  empty  places  in  the  spec- 
trum, which  black  spaces  are  the  Fraunhofer  lines. 

If  now  the  moon  crosses  a  straight  line  joining  the  centers 
of  the  earth  and  sun,  at  such  a  distance,  from  the  earth  as  to 


RADIANT     ENERGY.  103 

"fit"  the  sun,  the  entire  disc  will  be"  cut  out,  leaving  the  carbon 
layer,  the  chromosphere  or  the  layer  of  permanent  gases  above 
it,  together  with  all  other  clouds  and  layers,  and,  lastly,  the  corona 
in  plain  sight  for  the  few  minutes  of  total  eclipse.  Within  two 
seconds  before  the  exact  instant  of  totality  the  following  side  of 
the  moon,  just  going  before  the  sun's  disc,  will  cover,  and  two 
seconds  later  the  advancing  side  will  also  cover  the  carbon  ring 
around  the  sun,  cutting  off  its  brilliant  light.  What  happens 
from  the  laws  of  Kirchhoff?  The  reversing  layer  that  caused 
the  Fraunhofer  dark  lines  will  now  emit  bright  lines  of  its  own, 
and  these  bright  lines  flash  out  with  great  brilliancy  through  the 
whole  length  of  the  spectrum  and  the  glorious  sight  will  be  on  dis- 
play two  seconds  or  until  the  edge  of  the  moon  covers  this  layer 
also  and  cuts  off  the  brilliant  scene.  This  is  the  flash  spectrum,  and 
a  spectroscopist  will  journey  to  the  ends  of  the  earth  to  see  it. 

The  flashing  spectrum  was  first  seen  by  Professor  Charles 
A.  Young  at  the  total  eclipse  of  the  sun  in  Spain  on  December 
22,  1870.  When  the  moon  had  almost  hidden  the  sun,  the  black 
lines  were  still  visible,  but  at  the  exact  moment  of  second  contact, 
when  totality  occurred,  he  saw  the  usual  black  line  solar  spectrum 
disappear  when : 

•  "All  at  once,  as  suddenly  as  a  bursting  rocket  shoots  out 
its  stars,  the  whole  field  of  view  was  filled  with  bright  lines,  more 
numerous  than  one  could  count." — Young. 

Therefore,  KirchhofFs  law  was  actually  proven  to  act  on  the 
sun  as  well  as  in  the  same  experiment  in  terrestrial  spectroscopic 
laboratories.  The  flash  has  been  seen  at  subsequent  eclipses  and 
lines  mapped. 

Cut  41  is  the  wonderful  flash  spectrum  secured  by  Mr.  "J. 
Evershed,  at  Talni,  India. 

What  height  of  human  skill  and  trained  work  was  required 
to  take  this  photograph  at  once  the  carbon  ring  was  covered  and 
before  the  rapid  moon  had  time  to  encroach  upon  the  reversing 


104. 


RADIANT     ENERGY. 


Cut  41.     Flash  and  Cusp  Spectra  Compared.     Ultra-Violet  Region  I,    4100  to  I,  3350. 
Enlarged  Four  Times  From  Negatives  Nos.  3  and  1. 


layer  above !  Thus  Mr.  Evershed  had  four  complex  instruments 
before  him,  all  having  to  be  manipulated  with  extreme  accuracy ; 
yet  he  secured  thirteen  photographs  in  one  and  one-half  min- 
utes. The  nervous  strain  is  severe,  but  the  body  is  an  abject 
slave  to  will.  Cut  41  is  Evershed's  spectra,  the  lower  being  the 
ordinary  spectrum  an  instant  before  totality,  while  the  upper  is 
the  flash  or  reverse  spectrum  caught  on  the  rapid  plate  one1half 
second  later.  All  the  black  lines  in  the  spectrum  below  are 
reversed,  changed  to  bright  above.  They  coincide  end  to  end— 
they  are  direct  lines  from  the  gases  of  the  chromosphere.  These 
lines  are  from"  glowing  iron,  hydrogen,  calcium,  magnesium, 
helium,  titanium,  possibly  silicon  and  carbon,  with  others  ;  in  all, 
fifteen  modes  had  their  lines  changed  in  this  memorable  flash. 
It  will  be  seen  how  intimate  is  the  association  of  iron  and  hydro- 
gen in  the  solar  gases ;  a  great  fact  that  will  be  noted  under  the 
head  of  cosmical  and  stellar  evolution,  later. 


RADIANT     ENERGY. 


105 


Cut  42.    Thwait's  Graphs  of  Solar  Eclipse.     Exposure  Upper  1%  Sec., 
Lower  9  Sec.  at  Talni,  India.    Jan.  22,  1898. 


Cut  42  is  that  of  two  photographs  of  the  eclipsed  sun  and 
its  corona,  secured  by  Mr.  Thwait,  at  the  same  time.  The  upper 
is  an  exposure  of  one  and  one-half  seconds,  the  lower  nine  sec- 
onds, showing  much  greater  extension  of  that  mysterious  crown, 
the  crown  of  the  sun. 


io6  RADIANT     ENERGY. 


XV. 

MALE'S   SPECTROHELIOGRAPH. 

"He  plants  the  eye  of  Surya  in  the  sky,  and  disperses  the  delusion 
of  darkness." — Rig  Veda,  V.  40. 

"Bright-haired,  white-footed  steeds  draw  him  along  his  ancient  path 
without  dust,  and  built  secure,  the  golden-handed  bounteous  sun." — Rig 
Veda.  (Primeval  Aryan). 

This  remarkable  instrument  devised  by  Professor  George 
E.  Hale,  now  of  the  Yerkes  Observatory,  takes  accurate  graphs 
of  the  finer  details  of  the  apparent  surface  of  the  sun.  Not  only 
these,  but  the  photosphere,  chromosphere  and  the  prominences 
can  be  graphed  on  any  clear  day  without  waiting  for  a  total  solar 
eclipse.  This  invaluable  apparatus  takes  the  place  of  an  eclipse 
for  all  purposes,  except  graphing  the  corona.  Knowledge  of 
the  sun  was  greatly  augmented  by  the  invention  of  this  method 
of  solar  work  and  the  thanks  of  the  astronomers  of  the  earth 
have  already  been  rendered  to  Professor  Hale.  Its  principles 
ought  to  be  understood  by  all  who  admire  the  sun. 

Cut  43  is  a  graph  of  the  heliograph  as  it  appeared  in  Ken- 
wood Astrophysical  Observatory  in  Chicago,  before  Professor 
Hale  went  to  the  Yerkes  Observatory  at  Williams  Bay,  Wiscon- 
sin. It  is  attached  to  the  lower  end  of  a  twelve-inch  equatorial 
telescope,  the  same  as  the  telespectroscope  on  the  eye  end  of  the 
Lowe  telescope  (Tenth  Paper,  cut  23).  The  entire  disc  of  the 


RADIANT     ENERGY.  207 

sun  is  cut  off  before  the  slit  by  a  circular  plate  of  metal,  taking 
the  place  of  the  moon  at  eclipses.  The  plate  is  just  large  enough 
to  fit  or  cut  out  the  sun  and  its  photosphere,  leaving  the  chromo- 
sphere alone  and  the  explosions  entirely  around  the  circumfer- 
ence in  plain  sight.  And  Hale,  by  a  most  ingenious  arrangement 
of  double  slits,  photographs  them  all  at  the  same  time ;  then  he 
removes  the  metal  plate  and  photographs  the  sun  to  fill  up  the 


Cut  43.     Hales  Spectroheliograph. 

circle,  thus  securing  records  daily  of  all  phenomena  that  may 
appear  on  the  disc,  and  in  the  surroundings  except  the  corona. 
He  has  taken  many  hundred  graphs.  These  fill  the  minds  of  solar 
physicists  with  awe  and  wonder  at  the  complexity  of  the  sun. 
The  sun's  photograph  after  the  iron  plate  or  screen  is  re- 
moved, is  not  taken  at  once,  but  is  built  up  by  successive  narrow 
strips  of  photograph  secured  through  a  movable  slit  that  slides 


w8  RADIANT     ENERGY. 

across  the  image  of  the  sun.  The  effect  is  as  though  a  complete 
graph  of  the  sun  could  be  taken  at  one  instantaneous  exposure, 
for  not  only  is  the  disc  shown  with  minute  details,  but  the  chromo- 
sphere and  explosive  prominences. 

In  cut  43  the  first  slit  is  seen  at  I,  where  it  may  be  placed 
radially  or  tangen  tally  to  the  solar  image  as  shown  in  Chapter  X, 
cut  25.  This  slit  in  the  Kenwood  heliograph  is  3*4  inches  in 
length,  and  its  width  can  be  varied.  It  is  mounted  on  steel 
balls  so  it  can  be  moved  easily  across  the  image  of  the  sun, 
in  the  plane  of  dispersion  due  to  the  grating.  The  light  from 
the  sun  passes  through  the  slit  at  figure  i,  falls  on  the  grating 
in  its  box  at  3,  is  dispersed  into  a  spectrum  and  reflected  to  the 
slit,  just  under  the  sensitive  plate  in  its  holder  at  figure  2.  The 
slits  at  figures  I  and  2  move  in  opposite  directions,  with  the 
almost  incredible  effect  of  building  up  a  photograph.  In  graph- 
ing faculse  the  slit  upon  which  the  solar  image  falls  is  i~5ooth  of 
an  inch  wide.  This  slit  moves  at  right  angles  across  the  image 
just  below  figure  I — say  to  the  left;  then  the  slit  just  below  the 
plate-holder  at  figure  2  moves  to  the  right,  the  only  light  falling  on 
the  plate  at  any  one  instant  of  time  being  a  thin  line,  an  image 
of  the  slit.  To  make  the  motions  of  both  slits  coincide  in  exact 
time,  both  slit  plates  are  moved  by  the  same  power  which  is  due 
to  water  coming  in  from  a  pressure  through  the  rubber  tubes 
(4,  4).  One  pipe  leads  to  the  top  of  a  cylinder  (5),  which  con- 
tains a  piston  actuating  both  slit-holders,  Since  the  same  pressure 
of  water  moves  both  slits,  the  motion  is  synchronous,  and  the 
solar  image  is  graphed  with  equal  exposure  for  each  minute 
portion.  Hence  a  homogeneous  graph  is  made,  and  these  graphs 
have  elicited  the  admiration  of  all  scientific  men. 

The  arrangement  here  described  is  for  graphing  the  disc 
with  its  faculse  and  spots ;  but  if  the  prominences  and  chromo- 
sphere only  are  to  be  taken,  a  circular  disc  of  iron  just  large 
enough  to  fit  the  two-inch  image  of  the  sun  is  placed  about  where 


RADIANT     ENERGY.  109 

the  figure  i  appears.  This  cuts  out  the  solar  image  as  formed  by 
light  coming  through  the  end  of  the  telescope  at  figure  6.  Hale's 
spectro-heliograph  is  as  record  making  in  modern  astrophysics 
as  J.  J.  Thomson's  discovery  of  corpuscles  is  to  electricity  and 
to  the  universe,  and  as  Ramsay's  slow  but  sure  approach  to  the 
absolutely  zero  of  temperature,  is  to  the  root  and  foundation  of 
nature. 

Clearly  in  the  lead  of  all  are  his  exquisite  graphs  of  the 
faculse,  objects  scarcely  visible  in  the  telescope  without  the  helio- 
graphic  attachment.  These  are  inconceivably  hot  figures,  ar- 
ranged like  blazing  torches  over  the  mighty  disc  of  the  sun.  Their 
brilliancy  is  far  more  intense  than  in  adjacent  regions. 

When  all  is  ready  with  the  apparatus,  graphs  are  secured  at 
the  rate  of  one  per  minute,  where  before  it  required  an  hour  to 
get  a  poor  imprint  of  the  sun.  Evanescent,  fleeting  and  transitory 
objects,  explosions,  currents,  cyclones  and  hurricanes  are  at  once 
caught  in  their  impetuous  turbulence  and  appalling  fury,  and 
instantly  brought  to  a  state  of  rest,  like  instantaneous  graphs  of 
a  cataract  where  the  troubled  water  seems  to  be  without  motion. 
A  complete  history  of  an  explosion  40,000  miles  wide  and  200,000 
high  is  written  by  its  own  light.  White-hot  masses  many  times 
larger  than  the  earth  are  hurled  to  these  heights  with  speeds 
ranging  from  50  to  200  miles  per  second.  Up  and  up  rises  the 
awful,  seething  mass,  but  every  move  is  photographed. 

There  are  now  many  heliographs  in  Europe,  notably  at 
Meudon  and  Potsdam,  so  that  almost  continuous  records  of  the 
sun  are  written  on  permanent  plates,  especially  since  the  graphic 
observatories  in  Sydney,  Australia,  have  joined  in  the  relentless 
conquest  now  on,  the  conquest  of  the  mysteries  of  the  sun. 

Professor  Charles  A.  Young  saw  the  calcium  lines  in  solar 
faculae  reversed  in  1872.  Hale  now  graphs  them  without  diffi- 
culty. The  H  and  K  Fraunhofer  lines,  due  to  calcium  at  terrific 
heat,  are  reversed ;  that  is,  they  become  bright.  And  the  inevit- 


no  RADIANT     ENERGY. 

able  hydrogen  also  appears.  But  reversal  implies  a  force  at  work 
utterly  beyond  the  brain  of  man  to  comprehend.  The  faculse 
are  so  incredibly  hot  that  if  there  are  cooler  gases  above  they 
are  powerless  to  absorb  the  fierce  light  and  thus  cause  a  Fraun- 
hofer  dark  line ;  or  else  the  hot  material  is  hurled  up  entirely 
through  all  inclosing  layers,  in  the  nature  of  white  prominences, 
at  such  unheard-of  heat  that  their  corpuscles  cannot  vibrate  at 
their  own  rate — too  hot  for  that — so  give  the  well-known  continu- 
ous spectra  due  to  all  white  light.  But  they  are  made  of  calcium, 
a  leading  constituent  making  up  the  geologic  structure  of  the 
earth. 

Young  at  first  saw  reversal  of  the  lines  merely,  at  or  but 
slightly  removed  from  spots.  But  Hale  saw  reversed  lines  on 
the  disc  far  away  from  the  penumbra  of  the  spots.  He  conceived 
the  idea  because  the  reversed  lines  were  so  brilliant,  even  against 
the  effulgence  of  the  background  of  the  sun's  disc,  that  if  this 
glare  could  be  lessened  the  forms  of  the  faculae  could  be  appar- 
ently isolated  and  graphed.  This  he  actually  accomplished  with 
his  narrow  and  synchronously  moving  slits  and  rapid  plates.  The 
now  historic  day  arrived,  January  12,  1892 — Hale  photographed 
the  brilliant  faculse  on  the  sun.  These  colossal  areas  of  solar 
upheaval  are  now  graphed  at  all  hours  of  clear  days  with  little 
effort. 

The  most  noteworthy  thing  about  faculse,  aside  from  their 
excessive  brightness,  is  their  enormous  size.  Spots  large  enough 
to  take  in  thirty  worlds  like  the  earth  were  formerly  thought  to 
be  large,  but  the  "boiling-places,"  those  seething  cauldrons  of  the 
sun,  are  many  times  larger  in  area  than  the  largest  spots,  and 
they  show  at  all  parts  of  the  solar  disc,  while  spots  are  mostly  in 
equatorial  regions.  Human  ingenuity  seems  to  have  reached 
its  limit  here,  for  the  chromosphere  and  prominences  on  the  edge 
of  the  sun  are  less  brilliant  than  the  hotter  faculse,  and  therefore 
require  a  longer  exposure. 


RADIANT     ENERGY.  in 

The  circular  plate  of  iron  is  held  at  figure  I  to  cut  out  the 
sun,  when  the  slit  plates  are  both  driven  by  the  water  with  slow 
motion,  giving  long  time  exposure,  going  one  way  across  the 
image.  The  iron  disc  is  then  removed,  the  sun's  image  again 
falls  on  slit  plate,  water  flow  is  increased  and  the  slits  are  moved 


Cut  44.     Photograph  Made  With  the  Spectroheliograph  of  the  Kenwood 

Astro-Physical  Observatory,  Chicago,  by  Geo.  K-  Hale,  Chromosphere 

and  Prominences.     May.  24,  1892. 


with  greater  speed  in  the  opposite  direction  across  the  field  of 
view,  giving  short  exposure,  and  this  catches  the  faculae  and 
graphs  them  all  in  their  true  places.  The  entire  sun,  together 
with  all  phenomena,  are  thus  portrayed — a  thing  thought  impos- 
sible before  Hale  came  into  the  intellectual  arena  of  the  world. 
These  famous  graphs  are  imperfectly  represented  in  cuts 


IIP.  RADIANT     ENERGY. 


Cut  45.     Male's  Heliograph  Showing  White  Hot  Faculse. 


Cut  -40.     Kale's  Snapshot  of  Solar  Prominence.     March  24,  1892. 


RADIANT     ENERGY.  u3 

44  and  45.  Cut  44  (large  circle  of  sun)  is  where  the  slits  make 
their  first  excursion  across,  with  long  exposure — several  seconds 
— with  the  iron  plate  in  place  of  the  moon  at  eclipse ;  the  chromo- 
sphere and  a  few  prominences  appearing.  Cut  45  is  Hale's  photo- 
graph of  the  sun  showing  several  white  hot  faculse,  and  three  or 
four  prominences  on  edge.  Cut  46  is  a  snapshot  of  an  explosion 
on  the  sun.  Nearly  all  the  wonderful  details  of  the  sun,  as  seen 
on  the  original  negatives,  are  lost  when  transferred  to  paper. 


Cut  47.     Male's  Photograph  of  Solar  Prominences,  Showing  Rapid  Changes. 
Nov.  15,  1892. 

Cut  47  is  a  series  of  photographs  taken  November  15,  1892. 
Intervals  between  graphs  i  and  2,  five  minutes ;  2  and  3,  twenty- 
five  minutes;  3  and  4,  fourteen  minutes;  4  and  5,  one  minute;  5 
and  6,  two  minutes,  showing  rapidity  of  changes  in  prominences. 

He  also  made  a  most  remarkable  composite  drawing  from 
four  original  plates.  They  were  projected  on  a  white  screen  by  a 


I 1 4- 


RADIANT     ENERGY. 


Cut  48.     Kale's  Composite  Oraph  of  the  Sun. 


lantern,  thin  paper  being  placed  over  the  image  and  traced  with 
a  crayon.  The  four  pictures  are  thus  superposed.  Two  of  the 
negatives  showing  prominences  were  taken  at  9:15  and  9:59  a.  m., 
and  two  showing  faculse  were  exposed  at  9  and  9  :o6  a.  m.  Hale 
placed  a  blue  glass  in  front  of  the  slit  to  absorb  some  of  the 
light  of  the  photosphere,  thus  making  the  faculse  more  distinct. 

Here  is  a  quotation  from  Professor  Hale:  "I  have  else- 
where remarked  on  the  great  size  and  extent  of  the  faculse  as 
shown  on  photographs  taken  with  the  spectroheliograph.  The 
negatives  made  with  the  blue  glass  absorbent,  however,  show  that 
my  estimates  have  been  too  small.  Faculae  hitherto  invisible  are 
now  seen  dotting  the  surface  of  the  sun  from  pole  to  pole.  The 
faint  faculse  do  not  appear  to  be  separate  and  independent  phe- 


RADIANT     ENERGY.  n5 

nomena;  for  over  the  whole  surface  of  the  sun  they  seem  to  be 
connected  like  the  meshes  of  a  net,  though  the  forms  of  the 
inclosed  spaces  are  very  irregular." 

It  is  hoped  that  some  of  the  marvelous  network  can  be  seen 
when  cut  48  is  transferred  to  the  printed  sheet. 

And  now  a  ceaseless  record  of  the  sun  is  being  made  in 
countless  heliograms  throughout  the  world. 


n6  RADIANT     ENERGY. 


XVI. 
SOLAR   SPOTS. 

"The  sun  rises  out  of  life  and  sets  into  life." — Brihad  Upanishad, 
vi-2  (Hindu). 

"The  light  of  the  sun  is  the  soul  that  moves  or  rests." — Rig  Veda. 
B.  C.  1500  Aryan. 

"Thou  in  the  form  of  sunbeams,  preserves!  the  world." — Vishnu 
Purana  (Hindu  B.  C.  800). 

"The  sun  sinks  in  the  ocean,  and  azure-hued  vapors  arise ;  it  is 
Nature's  incense  of  devotion  perfuming  the  skies." — Anwari  Palinodia, 
Persian  Scriptures. 

These  have  been  watched  with  ever-increasing  interest  since 
the  invention  of  solar  eye-pieces  for  telescopes  and  with  renewed 
activity  since  the  appearance  of  the  solar  spectroscope  and  spectro- 
heliograph.  They  are  periodic.  The  average  period  obtained 
from  many  years'  observation  is  eleven  years  and  two  months. 
Sometimes  it  is  near  thirteen,  and  at  others  near  ten  years.  The 
maxima  occurred  in  1848,  '60,  '70,  '81,  '92  and  another  is  due  in 
1903. 

This  period  of  eleven  years  and  two  months  is  composed  of  two 
unequal  parts ;  there  are  on  an  average  six  years  between  max- 
ima and  minima,  and  five  years  from  minima  to  maxima,  thus 
the  period  of  increase  is  shorter  than  decrease. — Angot,  Aurora, 
page  94. 


RADIANT     ENERGY.  nj 

A  normal  spot  is  composed  of  the  dark  umbra  in  the  center 
and  this  is  surrounded  by  the  penumbra,  somewhat  lighter  col- 
ored and  in  the  center  of  the  black  umbra  still  blacker  dots  are 
seen  called  nucleolL  With  high-power  telescopes  the  umbra  is 
at  times  seen  covered  with  filmy  vapors,  apparently  floating  over 
from  the  photosphere.  A  majority  of  spots  are,  however,  so  ir- 
regular in  shape  that  they  are  not  the  typical  form.  The  umbra 
looks  black  in  the  telescope,  but  Langley  compared  the  light  from 
the  nucleus  with  the  surface  of  liquid  Bessemer  steel  in  a  blast 
furnace,  and  found  that  the  black  center  of  a  sun  spot  is  brighter 
than  a  calcium  light,  and  its  blackness  is  due  only  to  contrast. 
Astrophysicists  are  now  nearly  all  agreed  that  spots  are  depres- 
sions in  the  photosphere,  filled  with  cooler  and  therefore  heavier 
gases.  And  when  they  pass  the  edge  of  the  disc,  owing  to  rota- 
tion of  sun,  they  are  seen  at  times  to  be  deep  enough  to  cut  out  a 
notch. 

The  penumbra  is  composed  of  long,  separate  filaments  or 
streams  of  intensely  hot  matter  from  the  adjacent  photosphere, 
pouring  over  like  a  gigantic  cataract.  This  process  in  time  usually 
fills  or  submerges  the  spot. 

They  are  not  deep,  ranging  from  500  to  2,500  miles,  seldom 
so  deep  as  the  latter.  Minute  spots  are  in  diameter  from  500  to 
T,OOO  miles,  while  others  are  seen  almost  daily,  at  maxima,  in 
diameter  from  40,000  to  60,000  miles.  At  times  the  penumbra 
has  been  measured,  showing  width  of  150,000  miles. 

The  actual  beginning  of  a  spot  is  rarely  seen ;  they  com- 
mence in  a  minute  black  speck  and  rapidly  expand.  The  penum- 
bra does  not  appear  until  the  umbra  is  complete.  If  the  spot 
is  caused  by  an  upheaval  it  breaks  into  separate  fragments,  all 
of  which  keep  up  with  the  turning  of  the  sun  on  its  axis.  When 
a  spot  is  about  to  come  to  an  end,  a  jet  or  tongue  of  white  hot 
matter,  usually  the  end  of  a  facula,  starts  to  cross  the  fearful 
chasm.  These  are  termed  bridges.  They  rapidly  grow  wider, 


J     -i_I :  'SRK'W  ^  ^W*  •  v" 


-•;     .e     f. 
^J,t  *   »  -. 


2         > 


* 


<& 


. 


: 


Cut  49.    Sun  Spot,  Showing  Changes  at  1,  2,  3  and  4.    5  is  a  Spot 
and  Facula  on  Western  I,imb  and  6  on  the  IJastern. 


RADIANT     ENERGY.  ng 

others  start,  and  then  there  is  a  continual  flood  of  hot  material 
from  the  photosphere,  and  this  bends  or  pours  down  the  penum- 
bra to  the  yawning  umbra,  and  the  spot  vanishes,  an  exceed- 
ingly brilliant  facula  taking  its  place. 

Cut  49,  figure  i,  is  a  twisting  spot  drawn  by  an  observer 
February  n,  1892,  at  the  last  maximum.  Figure  2,  is  Feb- 
ruary 1 2th,  3,  1 3th,  and  4,  the  I4th.  Cyclonic  motion,  bridges, 
filaments  and  jets  are  well  seen.  The  sun  turns  from  west  to 
east,  opposite  to  the  motion  of  the  hands  of  a  watch.  Figure  6, 
cut  41,  is  a  large  spot  coming  on  east,  and  figure  5  is  the  same 
spot  going  off  west  after  an  interval  of  12  3-4  days  if  the  spot 
is  somewhere  near  the  equator.  For  the  equator  revolves  in  less 
time  than  the  surface  of  the  sun  in  either  latitude.  Thus  by 
watching  a  spot  in  latitude  45  degrees  the  spot  will  require  12.63 
days  to  cross,  that  is,  the  sun  revolves  in  25^  days  at  the  equator 
and  27^4  clays  in  latitude  45  degrees.  The  sun  is  not  solid,  there- 
fore, for  all  parts  of  a  solid  globe  revolve  in  the  same  time. 

The  cause  of  variations  in  solar  rotation  is  not  known,  but 
vast  currents  in  the  equatorial  regions  seem  a  plausible  theory, 
these  flowing  east,  or  currents  in  both  latitudes  flow  west. 

The  spots  in  figures  5  and  6,  cut  49,  are  surrounded  by 
the  outlines  of  immense  faculse.  Some  spots  appear  and  vanish  in 
a  few  hours ;  others  in  a  few  days.  Many  make  one  or  two  cir- 
cuits with  the  sun,  and  one  was  seen  to  make  18  revolutions  be- 
fore the  faculse  and  torrents  from  the  photosphere  finally  con- 
quered. Spots  are  confined  to  two  zones  35  degrees  wide  be- 
tween 5  and  40  degrees  in  either  north  or  south  latitude.  None 
have  been  seen  near  the  poles,  while  faculse  are  shown  in  Male's 
graphs  near  both  poles.  The  corona  also  stands  out  from  both 
solar  poles. 

In  cut  50,  a  spot  coming  to  an  end  is  shown,  with 
many  bridges  starting  across  in  all  directions,  while  cut  51  is 
a  new  spot,  with  only  one  jet  starting  in  the  lower  portion.  The 


120 


RADIANT     ENERGY. 


-'.*•  frt- 

%;   ? 


Cut  50.     Sun  .Spot  Coming  to  an  Kiid.     Bridge  Crossing  Umbra. 


3     % 
.'1' 


Cut  51.     Sun  Spot  Just  Formed.     No  Bridges. 


ENERGY.  121 

dots  on  each  cut,  50-51,  are  true  dimensions  of  the  earth. 
Veiled  spots  are  seen,  large  submerged  areas,  covered  by  thin 
cloud-like  forms,  as  though  they  could  not  appear  clearly  through 
them,  and  these  are  usually  enclosed  round  about  by  white-hot 
seething  faculre.  One  at  the  telescope,  viewing  an  active  spot,  can- 
not actually  see  the  jets  move,  any  more  than  the  motion  of  the 
hour  hand  of  a  clock,  but  going  away  and  returning  in  a  half  hour, 
the  rotary  displacement  is  noticed  at  once,  or  straight  line  ad- 
vance, if  a  bridge  or  jet  is  on  the  way  across. 

Many  theories  have  been  given  to  explain  solar  spots  or  de- 
pressions, but  none  are  free  from  objection.  Faye  thinks  they 
are  terrific  cyclones  twisting  up  matter  like  a  waterspout  at  sea ; 
this  cools,  falls  back  denser  and  shuts  out  light  from  below. 

Secchi  maintains  that  violent  explosions  occur  around  the 
place  where  a  spot  is  to  appear,  drawing  vast  quantities  of  mat- 
ter laterally,  and  allowing  the  undisturbed  portion  near  the  center 
to  sink  into  the  cavity,  and  then  the  portions  hurled  up,  fall  into 
this  depression,  cooler  from  their  journey  of  a  hundred  thousand 
miles  or  more.  Professor  Charles  A.  Young,  an  authority  on 
solar  matters,  advocates  this  hypothesis. 

At  first,  the  "motion  of  the  center  of  a  spot  is  inward  not  out- 
ward."—  (Young.)  This  is  known,  for  the  spectroscope  at  once  re- 
veals whether  a  source  of  light  is  advancing  or  receding.  The 
spot  spectrum  shows  the  solar  lines,  but  much  widened,  and  the 
terrific  vortex  of  hydrogen  presents  the  lines  bright  in  some 
cases.  Therefore  there  is  but  little  absorption  of  hydrogen  in  the 
umbra.  But  approach  of  hydrogen  with  the  unheard-of  speed  of 
300  miles  per  second  has  been  seen  at  or  near  the  edges  of  the 
spots,  while  a  downrush  was  noted  in  the  center. 

The  mystery  of  sun  spots  is  by  no  means  settled,  but  this 
ascent  and  descent  presents  a  most  impressive  picture  of  the  grand 
scale  upon  which  the  circulatory  gases  of  the  solar  disc  take 
place. 


122  RADIANT     ENERGY. 


•:;':v 


Cut  52.     Professor  S.  P.  I,angley's  Magnificient  Sun  Spot.     (Drawing.) 

Cut  52  is  one  of  the  most  magnificent  drawings  of  a  sun  spot 
ever  made.  The  marvelous  tongues,  filaments,  jets  and  spray 
over  the  black  abyss  are  beyond  comprehension.  All  over  the  ad- 
jacent regions  are  shown  the  "rice  grains"  and  rough  granula- 
tions always  seen  on  the  sun.  This  superb  delineation  was  made 
by  Professor  S.  P.  Langley  at  Allegheny,  Pa.,  Observatory.  It 
is  still  admired  by  solar  physicists  throughout  the  world. 


. — Readers  of  this  series  are  specially  requested  to  study 
and  fully  understand  the  properties  of  that  wonderful  space,  the 
magnetic  field,  before  the  next  paper  appears.  It  will  be  on  the 
effect  on  the  earth  caused  by  these  jets  across  sunspots.  The 
effect  is  magnetic,  therefore  the  electro-magnetic  field  should  be 
comprehended.  Any  work  on  electricity  or  higher  physics  will 
give  the  explanation. 


RADIANT     ENERGY.  123 


XVII. 
JETS  ON  THE  SUN— THEIR  EFFECT  ON  THE  EARTH. 

In  the  sky's  framework  she  has  shone  with  splendor 
The  goddess  has  cast  off  the  robe  of  darkness, 
Waking  up  the  world  with  ruddy  horses. 
Upon  her  well-yoked  chariot  Dawn  is  coming  in. 
';j  — A  Rishi's  Hymn  to  Dawn,  Rig  Veda  (1-113). 

And  rival  tempests  rush  amain 
From  sea  to  land,  from  land  to  sea, 
And  raging  form  a  wondrous  chain 
Of  deep,  mysterious  agency. 

— Michael  in   Goethe's   Faust. 

And  other  suns  perhaps, 

With  their  attendant  moons  that  will  descry, 
Communicating   male   and    female   light 
Which   two   sexes  animate  the   world. 

— Milton. 

The  immediate  effect  is  now  known  to  be  electro-magnetic. 
The  results  of  a  century  of  observation  all  point  to  this  conclusion. 
When  a  mighty  tongue  of  white  hot  matter  darts  across  the  abyss 
of  a  large  spot  or  cavern  on  the  sun,  the  equilibrium  of  the  earth's 
magnetic  field  is  disturbed  and  the  effect  is  a  magnetic  storm. 
The  needles  of  magnetographs  throughout  the  world  shiver,  trem- 
ble and  oscillate.  The  vibrations  take  place  on  opposite  sides  of 
the  earth,  the  impulse  not  requiring  time  that  can  be  measured, 
to  pass  from  the  side  of  the  earth  nearest,  to  that  most  distant 
from  the  sun,  whether  through  or  around  it. 


124.  RADIANT     HN  HRGY. 

These  magnetic  instruments  are  self-recording,  so  no  elec- 
tro-magnetic wave  from  the  sun  can  strike  the  earth  without  mak- 
ing its  own  record  in  the  electro-magnetic  observatories.  These 
are  separate  buildings  and  the  framework  is  bound  together  with 
copper  nails,  no  iron  being  allowed  near  the  delicate  apparatus. 
The  oscillations  of  the  needles  are  recorded  bv  automatic  photo- 
graphic mechanism  driven  by  clocks,  and  are  complex  in  detail. 
They  have  rendered  valuable  knowledge  of  pulsations  on  the  sun. 

After  three  centuries  of  investigation  from  Gilbert  to  Tesla, 
this  most  wonderful  space  is  still  the  admiration  and  inscrutable 
mystery  of  all  who  study  that  vast  science,  electro-dynamics. 
Power  is  cut  out  of  this  space,  and  the  hurrying  waves  are  caught, 
dragged  from  seemingly  void  areas  and  chained  to  servitude  in 
the  electric  light  and  railways.  But  the  sun  is  electro-magnetic 
and  waves  carrying  power,  beat  and  surge  against  the  earth.  A 
magnetic  field  is  space  surrounding  a  magnet.  This  space  may  be 
filled  with  air,  wood,  stone,  glass,  or  may  be  a  vacuum,  but  the 
waves  are  not  quenched.  They  flow  through  all  these.  A  freely 
suspended  magnet  in  a  magnetic  field  will  move,  and  the  earth's 
surface  is  surrounded  by  a  magnetic  field,  which  is  acted  upon 
by  solar  magnetic  energy.  A  free  magnet  will  place  itself  parallel 
to  straight  line  of  magnetic  energy,  or  tangent  to  a  curved  line. 
For  all  magnetic  energy  round  a  magnet  moves  in  lines. 

Cut  53  shows  two  poles  and  the  resulting  curved  lines  in  the 
adjacent  space.  The  black  square  represents  a  plate  of  glass 
lying  on  the  poles  of  a  vertical  U  magnet.  Iron  filings  are 
dusted  on  the  glass,  when  the  waves  or  lines  of  magnetism  at  once 
arrange  them  into  the  curves,  the  curvature  being  caused  by 
mutual  attraction  of  the  poles.  If  one  pole  is  used,  the  iron  parti- 
cles will  be  arranged  into  straight  lines  radiating  in  every  direc- 
tion. Suspend  a  sewing  needle  by  a  silk  fiber  in  the  field  (cut  53) 
and  it  will  at  once  place  itself  tangent  to  the  curves  and  come 
lo  rest.  But  let  the  field  be  disturbed — that  is,  become  stronger 


RADIANT     ENERGY.  125 

or  weaker — and  the  needle  will  move.  This  is  a  magnetic  storm. 
And  when  a  jet  is  hurled  across  a  spot  on  the  sun  the  disturb- 
ance reaches  the  earth  in  the  same  time  that  light  does — so  radi- 
ance traveling  186,000  miles  per  second — reaches  the  earth  in  eight 
minutes  nineteen  seconds.  The  terrestrial  field  responds  at  once 
and  every  magnetic  needle  on  earth  begins  to  swing,  the  photo- 
graphic plate  recording  every  beat,  and  the  clock  records  the  time, 
so  the  history  is  complete.  And  here  again  it  is  impossible  to 
refrain  paying  another  tribute  to  the  invaluable  aid  of  photog- 


Cut  53.     Magnetic  Poles  and  Field. 

raphy  to  science.  But  when  the  times  recorded  by  the  clocks 
are  reduced  for  differences  in  longitude,  the  absolute  time  of 
storm  is  the  same  for  all. 

MEMORABLE   MAGNETIC  STORM,,  NOVEMBER   I/,    1882. 

This  was  one  of  the  most  violent  on  record.  On  November 
15,  1882,  after  an  interval  of  cloudy  weather,  a  view  of  the  sun 
was  secured.  An  enormous  spot  was  at  once  seen  already  ad- 
vanced on  the  eastern  solar  limb  24  degrees.  It  was  in  a  state 
of  excessive  turbulence,  since  none  of  the  jets  were  straight,  but 
were  twisted,  crossed  and  contorted  in  every  shape.  The  edges 


j26  RADIANT     ENERGY. 

of  the  chasm  were  notched  and  indented,  while  the  umbra  was 
traversed  by  bridges,  filaments  and  photospheric  debris.  The 
spot  seemed  to  be  in  rotation,  confirming  the  theory  of  vortex 
or  whirlpool  motion,  for  striae,  granulations  and  tufts  of  incan- 
descent matter  were  strewn  about  the  inclined  or  depressed  sides 
of  the  penumbra  as  though  impressed  with  the  centrifugal  tend- 
ency of  rotary  motion. 

Clouds  again  obscured  the  sun  until  8  a.  m.,  November  iQth, 
when  the  sky  became  clear  and  remained  so  four  hours,  during 


>:      ••  '        ., 

Cut  64.     Sun  Spot,  8:30  A.  M.,  Nov.  19,  1882.     Jets  Starting  From  Opposite  Sides. 
(Drawn  by  the  Writer.) 


which  the  drawings  (cuts  54  and  55)  were  made  with  eye  at 
telescope,  a  fine  six-inch  Clark  equatorial,  with  prismatic  solar 
eye-piece. 

The  disruption  of  the  spot  was  almost  complete,  since  the 
1 5th.  The  black  umbra  had  become  broken  into  four  masses  (cut 
54,  drawn  at  8:30  a.  m.,  November  iQth),  when  two  tongues 
were  seen  starting  across  from  the  lower  side.  At  9:30  a  jet 
of  inconceivable  brilliancy  started  over  the  abyss  from  the  upper 
side,  as  shown.  The  solar  prism  was  covered  with  black  glass  to 


RADIANT     ENERGY.  i2j 

protect  the  eye,  yet  this  jet  at  terrific  heat  was  too  bright  to  look 
at  for  more  than  an  instant  after  it  had  well  advanced,  but  at 
the  starting  was  not  so  brilliant.  It  became  brighter  as  it  moved, 
a  thing  not  understood.  The  lower  jet  also  advanced,  and  the 
awful  tongues  grew  brighter  and  brighter. 

At  10  a.  m.,  or  in  half  an  hour,  the  jets  were  as  shown  in 
cut  55.  They  had  approached  so  that  only  a  narrow  strip  of 
black  remained  between.  They  curved  toward  one  another,  and 
seemed  at  the  point  of  striking  in  collision.  It  was  watched  with 


Cut  55.     10  A.  M.,  Nov.  19,  1882.     White  Hot  Jets  About  to  Strike  Together. 


intense  interest  with  pencil  in  hand,  ready  to  depict  the  scene, 
just  to  occur,  when  a  cloud  came  across  the  sky  and  obscured 
the  wondrous  spectacle.  The  disappointment  was  acute,  but  one 
common  to  astronomers.  On  the  next  day  the  two  jets  combined 
into  one  wide  bridge. 

The  spots  shown  in  cuts  54-55  are  merely  the  central  por- 
tions; there  were  108  smaller  spots  around  the  edges  of  the 
penumbra,  the  interior  edge  only  being  drawn, 


128  RADIANT     ENERGY. 

And  on  the  other  portions  of  the  sun  twenty-three  other 
spots  were  also  counted.  But  the  daily  press  of  November  I7th 
was  burdened  with  accounts  of  widespread  magnetic  disturb- 
ance, in  some  places  suspending  telegraphic  manipulation.  The 
area  of  turbulence  filled  that  great  quadrilateral  from  New  York 
to  Yankton,  Nashville  and  Winnipeg.  In  Milwaukee  the  carbons 
in  the  electric  lamps  were  lighted,  rendered  incandescent  by  cur- 
rents of  electricity  flowing  in  on  the  wires.  At  other  points, 
switch-boards  in  telegraph  offices  were  set  on  fire  and  keys  melted 
on  the  apparatus,  while  electric  balls  were  seen  hovering  on  the 
telegraph  in  Nebraska.  The  Atlantic  cable  was  in  a  state  ol 
unrest  and  more  or  less  disturbance  was  noted  in  Europe.  This 
now  historic  spot  was  38,000  miles  wide  and  87,000  long,  the  mean 
of  several  measures.  The  jet  at  the  upper  part  of  cuts  54-55 
therefore  traveled  19,000  miles  in  thirty  minutes. 

On  October  7,  1880,  Professor  C.  A.  Young  saw  an  outburst 
which  hurled  matter  vertically  to  a  height  of  300,000  miles,  but 
the  jet  of  November  19,  1882,  was  horizontal  across  the  spot. 
On  August  5,  1872,  he  also  saw  a  disruption  that  cast  up  white- 
hot  matter  at  a  rate  of  120  miles  per  second,  much  faster  than 
horizontal  speeds.  On  writing  to  Europe  he  received  reply  that 
British  magnets  were  in  agitation. 

Including  1882  there  were  three  great  magnetic  storms,  and 
these  coincided  almost  exactly  with  the  maximum  disturbance 
in  the  sun  spots.  However,  great  spots  have  been  seen  on  the 
sun  without  magnetic  unrest  on  the  earth,  and  conversely,  storms 
without  spots,  possibly  due  to  prominences  not  seen. 

The  first  and  now  classical  observations  of  these  phenomena 
were  made  September  I,  1859,  by  Messrs.  Carrington  and  Hodg- 
son in  England.  These  two  observers  were  many  miles  apart, 
but  both  happened  to  be  observing  the  sun  at  the  same  time. 
They  simultaneously  saw  two  objects  of  intense  brilliancy,  8,000 
miles  in  length,  2,000  in  width,  and  12,000  miles  apart,  suddenly 


RADIANT     ENERGY. 


I29 


Cut  56.     Total  Solar  Eclipse.    Short  exposure  Showing  Gases  Near  the  Sun  Only. 


appear  on  the  edge  of  the  umbra  of  a  gigantic  spot.  The  bright- 
ness of  these  was  five  or  six  times  that  of  the  adjacent  regions 
of  the  sun.  They  both  moved  side  by  side  over  the  spot,  36,000 
miles  in  five  minutes,  and  vanished.  These  were  detached  masses 
and  did  not  appear  as  continuous  jets.  A  great  magnetic  storm 
occurred  that  evening  on  the  earth,  and  also  a  magnificent  display 
of  the  aurora  borealis. 


i jo  RADIANT     ENERGY. 


XVIII. 
TERRESTRIAL  INFLUENCE  OF  SUN  SPOT  ACTIVITY. 

"Approach,  O  Vishnu !  enter  thine  own  body,  the  eternal  ether. 
Thou  art  the  abode  of  the  worlds." — From  Ramayana,  vii. 

Not  only  do  jets,  darts  and  bridges  across  cavernous  spots 
upset  the  equilibrium  of  the  earth's  magnetic  field,  thus  causing 
balanced  magnets  to  swing,  but  they  disturb  the  telegraphs  of  the 
world,  and  also  cause  displays  of  the  aurora  borealis?  and  at  times 
austral  as  well. 

Coincidence  of  auroral  splendors  and  solar  spot  action  is 
well  marked,  and  periodicity  is  clearly  established.  But  the 
aurora  is  known  to  be  electro-magnetic.  This  term  now  occurs 
so  often  in  scientific  literature  that  it  ought  to  be  understood  by 
all  who  wish  to  know  about  cosmical  physics. 

This  is  the  conservation  of  magnetism  from,  or  by  means  of 
electricity.  Magnetism  is  thought  to  be  a  vortex  in  corpuscles, 
and  if  the  vortex  can  be  suddenly  fixed  while  in  the  midst  of  its 
motion,  like  an  instantaneous  graph  of  falling  water  or  of  a  dyna- 
mite explosion,  the  result  will  be  a  permanent  magnet. 

Steel  permits  the  cessation  of  motion  and  fixation  of  cor- 
puscles within  its  particles  while  iron  does  not.  And  steel  is  iron 
with  the  addition  of  a  minute  quantity  of  carbon,  one  or  two  per 
cent  only.  The  mystery  hovering  round  about  carbon  lies  at  the 
root  of  nature,  for  the  chemical  union  of  carbon  with  iron  renders 


RADIANT     ENERGY.  i3i 

the  compound  susceptible  to  the  most  inscrutable  wave-motions, 
oscillations  and  pulsations,  surging  through  the  universe.  How 
can  we  clutch  corpuscles  and  chain  them  to  ordinary  chunks  of 
matter  usually  called  atoms,  and  thus  convert  them  into  perma- 
nent magnets? 


Cut  57.    Electro-Magnetic  Apparatus.     The  steel  needle  3  passed 
through  the  electric  coil  (2)  and  becomes  a  ma 


magnet  as  at  4. 


This  process  is  shown  in  cut  57.  No.  I  is  a  zinc  and  carbon 
cell  separating  electricity  from  matter  and  sending  it  out  on  the 
positive  wire,  whence  it  returns  to  the  negative  pole.  At  2,  the 
wire  is  coiled  around  a  glass  tube,  while  at  3  is  a  thin  piece  of 
steel  having  no  magnetism,  for  it  will  not  lift  up  iron  dust.  Close 
the  battery  circuit,  the  wire  becomes  a  center  of  electrical  energy. 
Pass  the  steel  through  the  tube,  take  it  out  at  4 — a  marvelous 


132  RADIANT     ENERGY. 

change  has  taken  place — it  will  hold  up  a  sewing  needle,  as 
shown !  This  has  remained  the  wonder  of  all  electricians  from 
Faraday  to  Edison.  What  mind  is  able  to  fathom  this  mystery? 

Every  wire  forming  a  connection  between  the  terminals  of  a 
source  of  electricity  is  surrounded  by  a  magnetic  field.  The  mag- 
netic energy  here  passed  through  glass  and  filled  the  tube  with 
its  lines.  The  steel  cut  them  out  and  fixed  their  potency  in  its 
particles,  and  became  a  permanent  magnet. 

The  steel  needle  (4)  has  also  acquired  a  remarkable  property 
in  relation  to  electricity,  for  if  it  is  placed  upon  a  pointed  support, 
as  at  5,  and  if  a  wire  (CD)  be  held  over  it,  then  will  the  needle 
(5),  turn  in  the  direction  (A  B)  if  the  battery  circuit  is  closed. 

Law.  A  magnet  free  to  move  places  itself  at  an  angle  with 
a  flow  of  electricity. 

This  is  deep  seated  in  nature,  and  is  the  cause  of  magnets 
moving  themselves  at  angles  to  currents  in  or  on  the  earth;  that 
is,  to  point  north,  for  if  the  steel  (4)  be  placel  at  6,  in  any  position, 
it  will  turn  to  point  north  if  left  to  itself.  There  must  be  a 
current  flowing  from  east  to  west  under  it,  and  since  the  earth 
turns  from  west  to  east,  the  sun  appears  to  move  from  east  to 
west,  and  the  sun  causes  the  earth  currents.  If  the  sun  is  torn 
and  tossed  by  storms,  disturbing  its  magnetic  field,  the  currents 
induced  in  the  earth  at  or  near  its  surface  will  vary,  and  this 
will  vary  the  potential  of  the  earth's  magnetic  field  and  cause 
magnetic  storms. 

Passing  of  the  steel  from  3  to  4,  through  the  electro-magnetic 
field  of  force  in  the  tube,  and  appropriation  of  magnetic  energy 
by  the  particles  of  metal  by  the  capture  of  corpuscles,  is  electro- 
magnetism.  It  pervades  nature. 

If  the  needle  (6),  anywhere  north  of  the  equator  of  the  earth 
be  suspended  as  shown,  without  making  its  south  end  heavier 
than  the  north,  then  the  north  end  will  dip  as  in  8,  9  and  10. 
Additional  steel  is  therefore  put  on  the  south  end  to  counteract 


RADIANT     ENERGY.  i33 

this  tendency,  if  a  horizontal  needle  is  wanted.  Dipping  needles 
are  always  inclined  by  an  angle  equal  to  the  magnetic  latitude, 
or  distance  of  the  needle  from  the  magnetic  equator  of  the  earth. 
In  10,  a  scale  is  attached  with  degrees  marked  so  this  angle 
can  be  read  in  any  place  on  earth,  while  7  is  complete  dip  circle, 
as  used  in  all  the  magnetic  observations.  South  of  the  earth's 
magnetic  equator  the  needle  would  point  the  other  way — that  is 
the  south  end  would  dip,  and  the  north  rise,  being  horizontal  only 
at  the  equator. 


N 


Cut  58.    Magnetic  Needle  Carried  Around  a  Magnet. 


This  may  be  seen  in  cut  58,  where  a  bar  magnet  is  shown, 
with  a  needle  near  it,  in  several  positions.  It  will  be  seen  that  the 
white  end  of  the  needle  is  opposite  the  plus  pole  of  the  magnet 
and  the  black  end  adjacent  to  the  minus  pole.  If,  therefore,  a 
magnet,  hung  on  a  pivot,  be  carried  from  the  north  magnetic  pole 
of  the  earth  south  across  the  equator  to  the  south  pole,  and  past 
that  round  through  the  equator  to  the  north  pole  again,  it  will 
make  one  complete  revolution.  In  cut  58  the  needle  is  shown 
as  having  made  half  a  revolution,  having  been  carried  half  way 
around. 

When  a  colossal  tongue  of  white  hot  matter  is  shot  across 
a  sun  spot,  the  needle  5,  in  cut  57,  will  swing  to  either  a,  b,  or  e, 
f ,  with  violence,  while  the  needle  9  will  vibrate  to  g,  h,  in  a  vertical 
plane.  This  is  a  magnetic  storm. 


i34.  RADIANT     BNBRGY. 

RECORD   OF    MAGNETIC   STORM    OF  JULY    l6,    1882. 

Made  at  Terminals,  New  York  and  Boston. 

Strengths  of 

Times.  Currents  in  Pressures 

h.  m.    (p.  m.)  Milli-Amperes.  in  Volts. 

12:37 27  100 

12:39 32  IJ8 

12:39^ 48  177 

12:40 44  163 

12:40*4 H4  492 

12:41 68  252 

12:43 20  74 

12:44 15  55 

12:45 19  7° 

12:46 14  52 

Resistance  of  line  wire,  2,700  ohms. 

Between  New  York  and  Providence,  R.  I. 

P.  M.  Currents  Pressures 

h.  m.  Milli-Amperes.        Volts. 

12:05 9  20 

12:07 42  113 

12:12 4.3  12 

12:15 .8  2 

12 :29 280  644 

This  is  a  most  impressive  record.  Thus,  from  New  York  to 
Boston,  the  line  resistance  was  2,700  ohmns,  yet,  when  terminals 
were  put  to  earth,  the  current  on  the  wires  due  to  the  storm  was 
strong  enough  to  register  133  milli-amperes  (thousandths)  at  the 
height  of  the  upheaval  on  the  sun.  And  between  New  York 


RADIANT     ENERGY.  i35 

and  Providence,  two  hundred  and  eighty-thousandths  of  an  am- 
pere, with  a  pressure  of  644  volts.  But  on  the  evening  of  July 
1 6th  a  grand  auroral  display  occurred,  and  a  vast  sun  spot  was  in 
turbulence  in  high  south  solar  latitude  and  near  the  western  limb. 
The  telegraphs  had  been  disturbed  from  New  York  to  Chicago 
and  Omaha  during  the  entire  week  before  the  culminating  storm 
and  aurora. 


136  RADIANT     BNBRGY. 


XIX. 

THE   AURORA   AND    SUN    SPOTS. 

"Thanks  to  the  light  of  the  rising  day,  to  the  dawn  longed  for, 
which  puts  an  end  to  the  anxieties  and  terrors  of  the  night." — Vedic 
Hymn  to  the  Dawn. 

"At  times  there  are  fire-glows,  sometimes  fixed  and  persistent,  some- 
times flitting.  There  are  Bothynoe,  when  as  within  a  corona,  the  fiery 
recess  of  the  sky  is  like  a  cave  dug  out  of  space.  There  are  Pithitse, 
when  the  expanse  of  a  vast  and  rounded  fire  is  either  carried  about  or 
glows  in  one  spot.  There  are  Chasmata,  when  a  certain  portion  of  the 
sky  opens,  and  gaping,  displays  the  flame  as  in  a  torch.  The  colors  of 
these  are  many.  Certain  are  of  the  brightest  red,  some  of  a  flitting 
and  light  flame  color,  some  of  white  light,  others  shining,  some  steadily, 
and  yellow  without  eruptions  or  rays.  Under  Tiberius  Csesar  the  cohorts 
ran  together  in  aid  of  the  colony  of  Ostia  as  it  appeared  in  flames,  when  the 
glowing  of  the  sky  lasted  through  a  great  part  of  the  night,  shining  dimly 
like  a  vast  and  smoking  fire." — From  the  Latin  author  Seneca,  Questiones 
Naturales.  Lib.  I.  C.  XIV.,  Capron's  Trans. 

"About  this  same  time  Antiochus  prepared  his  second  voyage  into 
Egypt : 

"And  then  it  happened,  for  the  space  of  almost  forty  days,  there 
were  seen  horsemen  running  in  the  air,  in  cloth  of  gold,  and  armed  with 
lances  like  a  band  of  soldiers. 

"And  troops  of  horsemen  in  array,  running  one  against  another  with 
shaking  of  shields  and  multitude  of  pikes  and  drawing  of  swords  and 
casting  of  darts." — Book  of  Maccabees,  II,  Chapter  V,  i,  2,  3. 

"There  was  a  bloody  appearance  of  the  heavens  which  seemed  like 
fire  descending  on  the  earth,  in  the  third  year  of  the  iO7th  Olympiad  and 
a  light  seen  in  the  nighttime  equal  to  the  brightness  of  day." — Pliny, 
Lib.  I,  C.  xxxiii. 

The  aurora  should  be  studied  with  care  by  means  of  every 
resource  known.  An  aurora  is  the  visible  effect  of  obscure  un- 
dulations from  the  sun,  that  source  of  waves,  as  they  come  dash- 
ing on  the  earth  with  a  speed  of  186,000  miles  per  second.  It  is 


RADIANT     ENERGY.  i37 

known  that  a  wave  of  light  is  a  wave  of  electro-magnetic  disturb- 
ance. In  a  six-months  winter,  say  at  the  north  pole  of  the  earth, 
the  sun  is  far  south  of  the  equator,  and  none  of  its  rays  can  shine 
on  the  earth's  northern  pole.  But  the  aurora  is  very  brilliant.  It 
shows  many  colors,  and  these  flash  and  glow  with  rapid  variations. 
The  light,  although  it  is  caused  by  the  sun,  does  not  come  direct, 
but  is  caused  by  the  turbulence  set  up  in  the  earth's  magnetic  field 
by  electro-magnetic  upheaval  on  the  sun.  The  field  of  the  earth 
is  "tuned"  for  that  of  the  sun,  as  are  coherers  in  sympathetic 
telegraphy  and  telephony.  The  aurora  is  known  to  be  electrical, 
for  magnets  and  compass  needles  on  ships  are  always  affected. 

No  magnet  can  be  placed  near  a  "current"  of  electricity,  or  a 
static  charge  without  making  oscillation.  If  a  bar  magnet  be 
broken  into  two  portions,  each  becomes  a  magnet  with  plus  and 
minus  poles.  If  each  piece  be  again  broken,  the  result  is  four 
magnets ;  if  each  of  these  is  divided,  there  will  be  eight  mag- 
nets, and  so  on,  and  there  will  be  as  many  magnets  as  there  were 
gross  atoms  of  steel  in  the  original  bar.  For  each  particle  has 
an  equator  and  poles,  and  is  animated  by  a  closed  circuit  of  mag- 
netic energy.  This  is  Ampere's  concept,  and  every  magnet  be«- 
haves  in  accordance  with  it. 

In  cut  59  there  appear  seven  Crookes'  wonderful  vacuum 
tubes,  with  which  he  approached  the  doors  of  a  labyrinth  lead- 
ing to  the  very  confines  of  matter.  The  air  has  been  pumped 
out  so  that  only  a  very  minute  quantity  remains.  Thus  while  the 
pressure  on  the  outside  is  fifteen  pounds  of  air  per  square  inch, 
it  is  only  a  minute  fraction  of  this  within.  The  ends  of  fine  plat- 
inum wires  have  been  pushed  through  the  sides  of  the  tubes  when 
the  glass  was  white  hot.  Now  connect  the  ends  of  the  platinum 
wires  to  the  terminals  of  either  a  static  electrical  machine,  or  an 
induction  coil  in  action,  all  in  a  dark  room.  Instantly  the  tubes 
light  up  with  supernal  radiance.  Their  beauty  is  beyond  descrip- 
tion. The  light  oscillates  with  great  rapidity;  they  glow  and 


RADIANT     ENERGY. 


CROOKE'S  TUBES. 


Cut  59.     High  Vacuum  Tubes. 


RADIANT     ENERGY.  i39 

blaze,  and  their  corruscations  are  the  wonder  and  admiration  of 
all  who  behold.  They  look  and  behave  like  the  oscillatory  dis- 
charges of  the  aurorse  hung  up  above  the  poles  of  the  earth.  The 
writer  has  lighted  these  tubes  hundreds  of  times  with  both  sources 
of  electrical  oscillations,  and  always  with  the  auroral  effect.  In 
the  ruby  tube,  the  imitation  aurora  is  shown  glowing  under 
the  action  of  high-pressure  electricity;  while  the  V-shaped  tube, 
No.  2,  looks  exactly  like  the  vertical  streamers  of  a  pulsating  au- 
rora. The  other  tubes  are  of  great  interest,  especially  in  that 
vast  region  of  research,  molecular  bombardment,  and  cannot  here 
be  explained  without  entering  upon  an  elaborate  treatise  on  mod- 
ern electricity.  Suffice  to  say  that  the  phenomena  on  display  in 
these  tubes  with  varying  rates  of  vacuity,  are  in  that  mystical 
place,  the  dim  borderland  between  radiant  energy  and  radiant 
matter,  if  indeed  there  is  any  boundary  between,  for  Thomson's 
corpuscles  and  Crookes'  electrons,  although  matter,  behave  like  ra- 
diant energy.  And  mystery  deepens,  for  both  Crookes  and 
Thomson  came  upon  the  same  bodies  smaller  than  atoms  by  dif- 
ferent methods. 

Cut  60  presents  nine  Geissler  tubes.  These  have  been  ex- 
hausted of  air  by  means  of  a  powerful  Sprengel  mercury  air  pump. 
Then  they  are  rilled  with  such  gases  as  nitrogen,  hydrogen,  oxy- 
gen and  the  hydro-carbon  series,  and  are  then  flashed  by  high  po- 
tential electricity  and  held  before  the  slit  of  the  spectroscope  for 
analysis  of  their  radiant  energy.  No  two  gases  vibrate  in  the 
same  rates  and  therefore  no  two  give  the  same  colors.  But  all 
rates  and  colors  ever  seen  in  auroral  streamers,  columns  and  cur- 
tains are  shown  in  rapidly  oscillating  electrical  discharges  in  these 
high  vacuum  tubes.  No  new  mode  is  seen  in  the  auroral  light. 

Nine  lines  have  been  seen  in  auroral  spectra,  but  not  more 
than  seven  at  once.  The  brightest  is  in  the  yellow-green,  but 
in  one  aurora  Perry  saw  the  red  brightest,  in  a  curved  streamer. 
A  magnetic  storm  was  raging  at  the  time,  while  Capron  saw  the 


140 


RADIANT     ENERGY. 


t's  Tubes     Filled  With  Hydrogen,  Oxygen  and  Other 
Permanant  Gases  for  Electrical  Researches. 


green-blue  flickering  in  all  parts  of  the  spectrum  of  the  same  dis- 
play February  4,  1872.  The  great  aurora  of  April  9,  1871,  was 
so  brilliant  that  measures  of  its  spectral  lines  could  be  made  with 
micrometer,  and  nine  were  measured.  In  every  aurora  the  green 
line  is  present,  while  the  others  vary  with  different  apparitions. 
The  red  line  in  the  auroral  spectrum  is  due  to  nitrogen,  ac- 
cording to  Vogel,  and  also  the  two  others  toward  the  violet.  The 
third  line  in  the  spectrum  of  oxygen  appears  as  the  fifth  in  the 
spectrum  of  an  aurora.  Most  of  the  lines  are  due  to  air  and  its 
gases.  But  iron  lines  appear  in  the  spectra  of  auroral  light  and 
the  mystery  is  how  can  iron  vapor  exist  in  air.  Vapor  is  made 
of  exceedingly  fine  particles,  so  fine  that  they  are  able  to  exist  in 
the  higher  regions  of  the  air  against  gravity  for  some  time,  or 
there  is  a  continual  precipitation  of  iron  dust,  at  least  during 
the  period  of  an  auroral  display. 


RADIANT     ENERGY.  141 

Nordenskjold  set  up  vertical  tin  tubes  in  the  Arctic  regions, 
and  caught  fine  particles  of  iron  from  space.  But  iron  is  the 
most  magnetic  metal — and  the  aurora  is  an  electro-magnetic  dis- 
turbance. 

Sounds  have  been  heard  at  times  of  auroral  displays,  and 
ozone  has  often  been  detected  by  its  odor.  This  can  be  made  in 
the  laboratory  at  any  time  by  the  action  of  electricity  on  oxygen. 
If  the  Crookes  or  Geissler  tubes,  when  the  electric  pressure  is  pass- 


cut  61.    Carl  Bock's  Aurora. 


ing  through  them,  be  placed  between  the  poles  of  a  powerful 
electro-magnet,  all  the  effects  are  intensified  and  the  colors  of  the 
lights  in  the  tubes  can  be  changed  to  imitate  the  colors  of  an 
aurora  by  simply  increasing  or  decreasing  the  strength  of  the  in- 
visible magnetic  field  in  which  the  tube  is  placed. 

Cut  61  is  a  drawing  of  a  magnificent  aurora  of  the  arch  and 
pulsating  type.     It  was  made  by  Professor  Caral  Bock  at  For- 


1 4.2  RADIANT     ENERGY. 

sanger  Fjord,  in  Lapland,  October  3,  1877.  The  sky  background 
is  green,  with  yellow  in  the  streamers.  The  wonder  about  this 
aurora  was  that  the  arch  remained  at  rest,  while  the  streamers  shot 
up  in  front  with  great  speed  and  lateral  undulation.  It  lasted 
two  hours.  The  axis  of  the  bow  or  arch  was  parallel  to  the  mag- 
netic axis  of  the  earth. 


RADIANT     ENERGY. 


XX. 

AURORAL  DISPLAYS. 

"For  before  sunsetting  chariots  and  troops  of  soldiers  in  their  armour 
were  seen  running  among  the  clouds,  and  surrounding  the  city."  Jgs- 
ephus,  "Wars  of  the  Jews,"  book  vi  15-3,  on  Vespasian,  Siege  of  Jerusa- 
lem. 

Aristotle,  De  Meteoris  Lib.  i,  Ch.  iv.,  describes  the  aurora 
as  an  "appearance  resembling  flame  mingled  with  smoke." 

Mathew  of  Westminster,  in  England,  A.  D.  555,  says  (An- 
nals of  Phil.,  Vol.  ix,  p.  250)  :  "Lances  were  seen  in  the  air." 
In  1656  pyramids  were  seen  in  England  in  "regionis  seris." 

In  Ireland  a  scarlet  aurora  was  thought  to  be  a  shower  of 
blood.  All  prodigies  seen  in  the  sky  that  were  in  motion,  re- 
corded in  the  history  of  the  world,  were  due  to  auroral  displays, 
aided  by  imagination.  Aurorse  seen  just  before  battles  were 
always  seen  to  be  legions  of  soldiers  coming  to  engage  in  ter- 
restrial war. 

SELECTION   OF  SPACE   WAVES   BY  THE  EARTH. 

This  is  all  that  is  necessary  for  the  earth  to  do,  or  man. 
The  fountain  is  the  sun  and  all  waves  of  whatever  length  are 
electro-magnetic.  For  if  the  two  ends  of  a  wire  are  connected 
to  the  opposite  poles  of  any  source  of  electricity,  the  regions 
round  about  the  wire  instantly  becomes  saturated  with  magnetic 
energy.  A  piece  of  steel  anywhere  in  this  field  will  select  some 


144  RADIANT     ENERGY. 

of  the  waves,  quench  their  motion,  store  the  energy,  and  when 
the  steel  is  removed  it  carries  the  energy  with  it.  Iron  cannot 
carry  energy  away  from  a  field. 

If  the  ends  of  two  different  kinds  of  metal  be  soldered  to- 
gether, and  one  of  the  ends  be  heated,  while  the  other  remains 
cool,  a  current  of  electricity  will  flow  if  the  other  ends  are  con- 
nected by  a  wire.  The  earth  contains  vast  quantities  of  metals, 
for  the  specific  gravity  of  the  whole  earth  is  much  greater  than 
that  of  any  rocks  on  the  surface  layers.  The  center  is  particularly 
dense.  There  must  be  vast  beds  of  unlike  ores  in  contact  not 
far  below  the  surface,  or,  indeed,  close  to,  or  on  the  external 
sheet.  These  are  warmed  by  the  sun,  and  thermo-electric  cur- 
rents are  set  up.  But  a  free  magnet,  either  over  or  below  a  cur- 
rent, or  anywhere  near  it,  moves  to  make  an  angle  with  it.  The 
stronger  the  current  the  greater  the  angle,  until  finally  a  right 
angle  is  reached.  If  the  current  varies  the  angle  varies  in  exact 
ratio.  And  the  magnetometers  of  the  earth  do  actually  change 
this  angle  every  day.  The  thermo-currents  flow  from  east  to 
west,  and  magnets  must  point  north  and  south  to  obey  the  law 
and  make  angles  with  them.  The  direction  of  magnetization  of 
the  earth  is  therefore  roughly  north  and  south.  The  auroral  dis- 
plays are  nearly  symmetrical  with  the  magnetic  poles  and  axis 
of  the  earth.  And  this  axis  is  roughly  parallel  to  the  axis  of 
the  sun,  while  the  axis  of  the  earth's  rotation  makes  an  angle 
with  the  sun's  axis  of  rotation.  The  sets  of  poles  and  axes  are 
not  coincident. 

Thermo-electric  currents  are  weak,  and  are  only  able  to  set 
up  minute  daily  variations  on  earth. 

THE   SUN   A  SPHERICAL,   MAGNET. 

Cut  62  is  an  inadequate  sketch  of  Professor  Frank  H.  Bige- 
low's  exploration  of  the  magnetic  field  surrounding  a  magnetized 
sphere.  He  finds  the  flow  from  plus  to  minus  hemispheres,  as 


RADIANT     ENERGY. 


indicated  by  the  arrows.  Let  the  sphere  be  the  sun,  then  to  the 
extreme  right  is  a  minute  dot,  the  proportionate  size  of  the  earth. 
It  is  being  struck  by  a  wave  front  of  magnetic  radiation  from  the 
sun,  which  disturbs  the  field. 

Below  the  sun  are  shown  two  terminals  of  an  induction  coil 
used  in  wireless  telegraphy  and  phony,  in  setting  up  waves.  To 
the  extreme  right  is  the  coherer,  in  a  distant  receiving  station.  It 
is  also  being  hit  by  the  same  kind  of  wave-making  impact  on 
the  earth.  The  wave  makes  the  loose  particle  of  metal  between 
the  knobs  in  the  glass  tube  cohere  into  a  wire  for  each  dot  and 


Cut  62.    Bigelow's  Spherical  Magnetic  Field. 


dash,  and  thus  switch  in  a  local  battery.  The  process  is  cutting 
waves  out  of  space. 

The  earth  and  coherer  are  both  doing  the  same  thing  with 
the  same  kind  of  waves,  known  to  be  electro-magnetic. 

The  sun  and  the  coil  evidently  do  the  same  kind  of  work; 
that  is,  an  explosion  on  the  sun.  The  zig-zag  between  the  knobs 
is  lightning,  has  a  pressure  of  750,000  volts  and  length  of  24 
inches  in  the  Los  Angeles-Avalon  space  telegraph,  and  42  inches 
in  the  distance  apparatus  just  installed  in  Japan.  The  disruptive 
discharge  is  oscillatory ;  that  is,  darts  both  ways  from  knob  to 
knob,  with  terrific  velocity  and  loud  snapping  noise — thunder. 


1 4.6  RADIANT     ENERGY. 

But  every  oscillation  sends  out  a  wave,  like  a  stone  falling  in 
water.  If  the  two  knobs  be  drawn  apart,  the  lightning  no  longer 
has  potential  great  enough  to  break  down  the  air,  so  it  expands 
into  a  brush  of  blue  light  electricity,  like  the  bristles  of  a  paint 
brush  if  widely  separated. 

Many  flashing  aurorse  have  been   seen  with   every  appear- 
ance of  a  brush  discharge. 


Cut  (>:->.     Curtain  Aurora. 


Cut  63  is  the  magnificent  curtain  aurora  drawn  by  Dr.  Hayes 
in  the  Arctic  regions  January  6,  1861.  Thus:  "The  space  within 
the  arch  was  filled  with  black  cloud,  but  its  border  brightened 
steadily,  though  the  discharges  were  capricious ;  now  glaring  like 
vast  conflagrations,  now  beaming  like  the  glow  of  a  summer 
morn.  More  and  more  intense  grew  the  light,  until  from  irreg- 
ular bursts  it  matured  into  an  almost  uniform  sheet  of  radiance. 
Toward  the  end  of  the  display  its  character  changed.  Lurid  fires 


RADIANT     ENERGY. 

flung  their  awful  portent  across  the  sky,  before  which  the  stars 
seemed  to  recede  and  pale." 

An  account  by  the  writer,  written  on  April  17,  and  widely 
published  in  scientific  journals : 

GREAT  AURORA   APRIL    1 6,    1 882. 

"April  16,  1882,  will  pass  into  the  history  of  astronomy  as 
an  eventful  day.  From  morning  to  night  the  solar  surface  was  in 
violent  agitation.  Colossal  centers  of  cyclonic  activity  were 
watched  in  telescope  during  the  entire  day.  There  were  in  spots 
counted  from  8  a.  m.  to  sunset,  the  largest  being  67,000  miles 
long  and  48,000  wide.  It  was  seen  on  April  i5th,  fifteen  degrees 
on  the  eastern  limb.  Throughout  the  I5th  it  did  not  display 
unusual  turbulence,  but  during  the  night  activity  set  in,  for  on  the 
next  morning  its  internal  structure  had  changed  completely.  It 
was  cut  into  four  portions  by  bridges  which  did  not  maintain 
Iheir  positions  for  an  hour.  They  were  widening,  contracting  and 
bending  into  ever-changing  forms.  They  were  much  whiter  and 
hotter  than  the  solar  disc.  At  9  a.  m.  two  tongues  were  seen 
pointing  toward  each  other  from  opposite  sides  of  the  spot.  At 
12:30  p.  m.  the  ends  of  the  jets  met  and  passed,  leaving  black 
space  between.  Shortly  after  they  began  a  curvature  toward  each 
other,  which,  at  2  p.  m.,  formed  a  circle,  clearly  a  cyclone. 

"At  9  p.  m.,  while  viewing  Wells'  comet  in  the  telescope,  it 
suddenly  vanished.  Looking  out  the  dome  to  observe  the  cause, 
its  obscuration  was  found  to  come  from  the  rapidly  rising  arc  of 
an  aurora.  The  advancing  apparition  presented  a  yellowish- 
green  arc  of  a  circle,  in  altitude  18  degrees,  half  way  to  Polaris, 
and  whose  ends  rested  on  the  eastern  and  western  horizons.  The 
width  or  the  arc  was  55  degrees  ;  clear  sky  revealing  Cassiopeia, 
being  below  it,  near  the  northeastern  horizon.  The  center  of  the 
arc  did  not  appear  to  be  in  line  below  Polaris,  so  its  deviation 
was  measured  with  the  declination  circle.  The  eastern  end  of 


148  RADIANT     ENERGY. 

the  arc  was  15,  and  the  western  25  degrees  north  of  the  equator, 
so  the  axis  of  the  arc  was  inclined  10  degrees  east  of  the  axis  of 
the  earth.  The  streamers  above  the  arc  were  parallel  to  the 
dipping  needle. 

"For  nearly  an  hour  the  phenomenon  developed  no  sign  of 
coming  grandeur,  but  at  10  p.  m.  three  pillars  of  crimson  light 
shot  up  to  an  altitude  of  40  degrees  from  the  western  extremity 
of  the  arc,  while  a  few  yellow  streamers  ascended  in  the  east. 
These  outbursts  seemed  to  be  a  preconcerted  signal  with  the 
celestial  pyrotechnists,  for  within  two  minutes  the  whole  arc 
flashed  and  trembled,  and  then  bodily  expanded,  ascending  eight 
degrees.  A  halt  was  made,  which  lasted  not  more  than  a  minute, 
when  two  flashes  in  rapid  succession  were  sent  throughout  the 
widened  arc,  now  20  degrees  broad.  A  mighty  upheaval  fol- 
lowed, the  apex  of  the  band  at  once  lifted  to  Polaris,  altitude  41 
degrees,  filling  the  northern  heavens  with  supernal  light  bright 
enough  to  read  by ;  but  the  terminals  on  the  east  or  west  did  not 
draw  nearer  the  equator,  the  energy  being  central.  The  great 
aurora  reserved  its  forces  a  few  moments,  and  then  discharged, 
simultaneously,  hundreds  of  columns  of  scarlet,  violet  and  light 
yellow  flames,  instantly  converging  at  the  zenith.  This  display 
waned  only  to  make  way  for  another  advance  still  more  mag- 
nificent, and  so  on  throughout  the  night,  outburst  succeeding  out- 
burst in  rapid  movement,  until  the  rising  sun  put  out  all  lesser 
glories. 

"From  midnight  to  I  a.  m.  the  action  was  at  its  height,  the 
whole  northern  heavens,  from  horizon  to  equator  being  belted 
and  banded  with  varying  streamers,  while  flashes  were  incessant. 
A  wave  would  appear  on  the  north  horizon  and  instantly  rush 
to  the  zenith.  Each  impulse  produced  curvature  in  the  straight 
columns,  which  at  once  became  straight  again  until  another  dis- 
turbance rose  up  within  a  few  seconds.  The  whole  northern 
hemisphere  quaked  with  the  rapidity  of  lightning  without  cessa- 


RADIANT     BN  HRGY.  i49 

tion  during  the  hour  of  maximum  unrest,  each  upheaval  hurled 
light  directly  to  the  zenith,  with  great  velocity,  whence  it  slowly 
drifted  south,  descending  as  far  as  Scorpio  in  the  southern  heav- 
ens, something  unusual  in  northern  auroras." 

Professor  S.  P.  Langley,  of  the  Allegheny,  Pa.,  Observatory, 
wrote  on  the  I7th :  "The  auroral  streamers  converged  to  a  point 
10  degrees  south  of  the  zenith,  while  the  fluctuating  light  seemed 
to  pour  upward  incessantly  like  a  pale  flame.  My  object  in  writ- 
ing is  not  so  much  to  describe  the  aurora,  however,  as  to  call 
attention  to  the  fact  of  its  coincidence  with  a  remarkable  sun 
spot,  which  is  now  visible  to  the  naked  eye  if  defended  by  a 
smoked  glass.  We  have  had  no  such  solar  visitant  for  over  ten 
years.  It  consists  (at  the  time  I  write)  of  two  large  and  five 
small  nuclei,  united  by  penumbrse,  traversed  by  "bridges"  of 
intense  brightness.  The  area  may  be  given  in  round  numbers,  at 
a  minimum,  as  a  thousand  million  square  miles."  The  heights 
of  aurorse  are  from  25  to  130  miles,  and  some  are  seen  in  America 
and  not  in  Northern  Europe,  and  vice  versa. 

Cut  64  is  a  most  valuable  record.  It  was  made  by  Professor 
Loomis  from  a  search  of  the  records  of  the  world.  It  shows  the 
number  of  sun  spots,  auroras  and  magnetic  storms  for  100  years, 
from  1775  to  1875. 

Figure  I  shows  the  number  of  auroras  by  the  height  of  the 
vertical  black  lines.  The  ordinates  (the  numbers  to  the  left),  are 
numbers  of  auroras.  Thus,  in  1786,  there  were  117,  and  in  1810 
only  four. 

Figure  2  is  the  average  range  of  magnetic  declination — that 
is,  the  number  of  degrees  the  needle  moved  every  day.  Thus 
in  1786  the  average  for  the  year  was  12  degrees  daily,  the  high 
column  in  figure  2  comes  under  the  high  number  of  auroras  above 
it  in  figure  I. 

In  figure  3  is  the  number  of  groups  of  sun  spots  in  1786, 
about  no  groups,  and  it,  too,  is  in  line  with  the  high  columns  of 


RADIANT     ENERGY. 


Fig:2.  LOOMIS 

JB2O  L83O  1H4.O  l».r>0  1860  187: 


Cut  64.     Record  of  Sun  Spots  and  Magnetic  Storms. 


auroras  and  storms  among  the  magnets.  The  lines  of  abscissas 
are  intervals  of  ten  years.  The  coincidence  is  complete.  In  1810 
they  were  all  reduced  to  a  minimum.  However,  in  1805  there 
were  quite  a  number  of  spots,  but  few  auroras,  while  in  1870  they 
agreed  again.  Another  spot  maximum  is  due  in  1903-4,  and  it 
is  hoped  the  earth  will  have  lively  auroral  and  electro-magnetic 
times. 


RADIANT     ENERGY.  i5i 


XXI. 

THE    SUN'S    POTENTIAL. 

"For  consider  Purna,  that  great  vault  of  space,  the  sun  shines  forth 
and  there  is  light,  the  clouds  gather  and  there  is  darkness,  the  winds 
arise." — Kiounen  Sutra,  Chinese  Scriptures. 

''But  if  darkness,  light  and  sight  be  separate  and  independent  one 
of  the  other,  then  if  you.  remove  light  and  darkness,  there  is  nothing 
left  but  void  space." — Buddhistic  Sutra. 

"As  one  sun  illumines  the  whole  world,  so  does  the  one  spirit  illumine 
the  whole  of  matter.  O!  Bharata."— Hindu  Baagavad-Gita,  Ch.  XIII. 

"When  I  see  the  sun  and  moon  in  eclipse,  and  the  wise  man  in  want, 
then  I  say  Fate  is  master." — Hindu  Hitopadesa,   I,  44-6. 

"Light,   seeking   light,   doth   light  of     light     beguile." — "Love's     Labor 
Lost,"  Act  I,  Sec.   I. 

LIGHT  POTENTIAL,  OF  THE  SUN. 

Many  measures  have  been  made  of  the  sun's  light  with  sev- 
eral kinds  of  photometers.  Its  intensity  has  been  a  source  of 
wonder  to  all  who  have  ventured  on  the  problem. 

Light  varies  inversely  as  the  square  of  the  distance,  and  the 
sun  is  93,000,000  miles  from  the  earth ;  therefore,  its  intensity  is 
inconceivably  greater  on  the  sun  than  here,  yet  will  destroy  the 
retina  of  the  eye  and  far  surpasses  any  light  that  man  is  able  to 
make. 

The  light  of  the  sun  comes  from  the  white-hot  carbon  enve- 
lope. But  not  only  is  a  part  absorbed  by  the  gases  above  it,  but 
its  character  is  changed  in  color  and  activity.  Professor  S.  P. 
Langley  has  shown  that  if  the  sun  had  no  atmosphere,  the  surface 
would  shine  at  least  two  or  three  times  brighter  than  it  does,  and 


152 


RADIANT     ENERGY. 


with  a  blue-violet  color,  like  the  light  of  an  electric  arc,  playing 
between  carbon  terminals.  Most  of  these  refined  researches  were 
made  by  Langley  on  Mount  Whitney,  California. 

Absorption  in  the  solar  atmosphere  can  be  seen  by  a  college 
class  at  the  same  time  as  shown  in  cut  65. 

This  represents  the  eye  end  of  a  telescope  whose  object  glass 
is  pointed  at  the  sun.  The  lenses  of  the  eye-piece  expand  the  light 
upon  a  card.  Make  two  holes  in  the  first  card,  one  in  the  center 


Cut  65.    Image  of  Sun  on  Screen. 


and  one  near  the  edge  of  the  solar  image,  and  receive  the  light  on 
another  screen.  If  the  brightness  of  the  spots  is  measured  by  a 
photometer  (light  measurer,)  it  will  be  found  that  the  brilliancy 
of  the  circle  near  the  edge  of  the  sun  is  only  two-fifths  that  in  the 
center,  having  passed  through  a  much  greater  depth  of  gases 
on  the  sun. 

Now  light  and  also  heat  or  any  other  radiance  varies  inversely 
as  the  square  of  the  distance  is  shown  in  cut  66,  where  the  in- 
tensity of  light  from  C,  falling  on  the  areas  (i,  2  and  3),  are 
equal.  But  the  space  in  2  is  four  times  and  in  3  nine  times  thai 


RADIANT     ENERGY.  i53 

in  i,  while  the  distances  are  2  and  3,  and  4  is  the  square  of  2  and 
9  of  3.  The  distance  of  the  earth  from  the  sun  is  equal  to  i,  and 
of  Venus  .72.  The  square  of  I  is  i,  and  of  .72  is  .52;  hence 
the  quantity  of  light  and  heat  received  from  the  sun  by  Venus 


Cut  66.     Variation 'of  Light  With  Distance. 

equals  i  divided  by  .52,  or  1.9,  almost  double  that  received  by 
the  earth.  Human  beings  could  not  live  on  the  equator  of  Venus. 
Great  skill  has  been  employed  in  the  measurement  of  radiance 
received  on  earth  from  the  sun.  This  is  done  by  comparison, 
as  may  be  seen  in  cut  67,  which  is  a  meridian  photometer  in  out- 


p^xT 
/^D 


Cut  67.     Meridian  Photometer  in  Outline.     From  Professor  Young. 


line,  for  the  measures  are  made,  when  the  sun  is  on  the  meridian, 
to  secure  the  least  depth  of  the  earth's  atmosphere,  and,  therfore, 
its  minimum  absorption.  Light  from  the  sun  is  reflected  by  the 
mirror  of  the  heliostat  through  a  lens  into  a  dark  room.  Rays, 


ENERGY. 

after  passing  the  focus  (F)  of  a  convex  lens,  always  diverge. 
Suppose  the  lens  to  be  half  an  inch  in  diameter,  it  will  form  an 
image  of  the  sun  on  the  screen  (S  S).  The  size  of  this  image 
depends  on  the  distance  of  the  screen  from  F.  Suppose  its  dis- 
tance is  such  that  the  circular  image  is  10  feet  in  diameter;  that 
is,  240  times  the  diameter  of  the  lens.  Then  the  illumination  of 
the  disc  on  the  sceen  will  be  i-57,6ooth  that  of  the  sun,  after 
allowing  for  absorption  by  mirror,  lens  and  screen,  for  240 
squared  is  57,600.  Place  a  rod  like  a  pencil  on  end  at  P  and  a 
standard  candle  at  C.  Move  the  candle  back  and  forth  until  the 
shadow  cast  by  the  pencil  at  I  equals  in  darkness  that  cast  by  it 
atj. 

Hundreds  of  measures  have  been  made  on  different  days 
with  varying  clearness  of  the  air,  when  it  has  been  found  that 
a  standard  candle  must  be  placed  at  a  distance  of  one  meter  from 
the  screen  to  make  the  two  shadows  equal,  one  by  the  candle, 
the  other  by  the  sun.  A  standard  candle  adopted  by  physicists 
is  made  of  sperm  and  burns  120  grains  per  hour,  or  7.776  grams. 

When  the  sun  is  on  the  meridian  and  allowance  is  made 
for  absorption  by  air  and  glass,  it  illuminates  a  screen  70,000  times 
as  strongly  as  the  candle.  The  distance  of  the  sun  is  150,000 
million  meters.  Square  this,  multiply  the  product  by  70,000  and 
the  result  comes  out  1,575,000,000,000,000,000,000,000,000  candle 
power.  This  is  the  quantity  of  light  emitted  by  the  sun,  anc 
is  different  from  intensity,  for  an  immense  surface,  even  if  not 
very  brilliant,  can  radiate  a  large  quantity  of  light,  while  the 
quantity  of  light  emitted  by  any  square  unit  as  a  square  inch 
or  centimeter  determines  the  intrinsic  brilliancy.  Computing, 
it  is  found  that  the  sun's  carbon  winding  sheet  is  190,000  times 
brighter  than  he  candle  flame  (Young)  and  150  times  brighter 
than  a  calcium  light,  and  from  two  to  four  times  more 
brilliant  than  the  electric  arc  light,  all  of  which  lights  appear 
as  dark  spots  when  held  between  the  eye  and  the  sun. 


RADIANT     ENERGY.  755 


XXII. 
HEAT   POTENTIAL   OF   THE    SUN. 

Whence  are  thy  beams,  O  sun ! 
Thy  everlasting  light.  — Ossian's  "Poem  to  the  Sun." 

Sunshine,  broken   in   the   rill, 

Though  turn'd  astray,  is   sunshine   still. 

— Moore's  "Lalla  Rookh"  ("The  Fire  Worshippers"). 

Substance,  and  accident,  and  their  operations, 

All  infused   together   in   such   wise 

That  what  I  speak  of  is  one  simple  light. 

— "Paradise,  XXIII,"   Longfellow's  Trans. 

There  is  only  one  Deity,  the  great  Soul. 

He  is  called  the  Sun,  for  he  is  the  soul  of  all  beings. 

—"Rig  Veda." 

The  glorious  lamp  of  heaven,  the  radiant  sun, 

Is  nature's  eye.  — Ovid's  "Metamorphoses,"  line  165. 

THE  PIEAT  OF  THE  SUN. 

Not  less  skill  has  been  employed  in  measuring  long  heat 
waves  than  in  short  light  undulations.  Many  eminent  physicists 
have  brought  instruments  of  ever-increasing  accuracy  to  the  task. 
Some  of  these  are  complex  and  too  technical  to  be  explained  here. 

Perhaps  the  simplest  and  first  of  all,  was  Pouillet's  pyro- 
heliometer  (sun-heat  measurer),  as  shown  in  cut  68,  where  A 
is  a  metal  cylindric  box  one  decimeter  in  diameter  and  of  a 
thickness  required  to  hold  TOO  grams  of  distilled  water.  The 


156  RADIANT     ENERGY. 

upper  surface  is  blackened  with  lampblack,  for  this  is  the  best 
absorbing  substance  known,  while  the  other  parts  are  of  polished 
silver,  for  this  is  the  worst  absorbing  metal;  the  object  being 
to  secure  all  the  radiance  possible  in  the  water  box.  The  bulb 
of  a  sensitive  thermometer  is  immersed  in  the  water,  the  tube 
serving  as  an  axis.  The  black  surface  of  the  box  is  placed  at 


Cut  68.    Pouillet's  Pyroheliometer. 


an  exact  right  angle  to  the  sun,  which  is  found  when  the  shadow 
of  the  box  coincides  with  the  circular  sheet  of  metal  B.  To  use 
it,  a  screen  is  held  between  box  and  sun  for  five  minutes.  The 
water  becomes  of  the  same  temperature  as  the  air  or  sky,  which 
temperature  is  read  on  the  air  scale  at  T.  The  screen  is  then 
removed  and  radiance  allowed  to  fall  on  the  black  box  for  five 


RADIANT     ENERGY.  757 

minutes,  when  screen  is  replaced  and  thermometer  again  read. 
The  difference  between  these  readings — the  first  and  second  five 
minutes — gives  data  for  temperature  raised  in  a  cylinder  of 
radiance  one  decimeter  in  diameter  in  100  grams  of  water  in 
five  minutes.  Were  it  not  for  allowances  to  be  made  for  the 
small  quantity  of  heat  not  absorbed  by  the  lampblack  and  the 
amount  absorbed  by  the  earth's  air  the  result  would  give  the 
amount  of  heat  that  escaped  the  sun's  atmosphere  and  fell  on 
the  earth. 

Violle's  actinometer  and  other  forms  are  more  accurate  than 
Pouillet's,  but  after  many  thousands  of  determinations,  by  all 
these  in  all  conditions  of  the  air  as  to  transparency,  dust,  water 
vapor,  etc.,  the  results  agree  fairly  well. 

THE  SOLAR  CONSTANT. 

This  is  the  result  of  a  hundred  years  of  research  and  is  the 
constant  or  invariable  quantity  of  heat  that  reaches  the  earth 
from  the  sun.  Its  quantity  is  beyond  all  concept.  It  surprised 
the  early  physicists  and  now  fills  with  awe  all  who  comprehend 
its  mighty  import.  But  really  none  can  comprehend. 

How  much  to  allow  for  absorption  in  the  atmosphere  was 
found  by  taking  a  bolometer  up  to  different  mountaiin  heights. 
This  is  one  of  the  most  remarkable  instruments  ever  invented, 
and  will  be  fully  described  just  before  the  subject  of  radiance 
from  the  stars  is  taken  up.  By  its  use  and  subsequent  mathe- 
matical computation  by  some  of  the  ablest  mathematicians,  the 
following  value  has  been  obtained : 

THREE   CALORIES. 

Thus,  Professor  S.  P.  Langley,  after  extended  and  accurate 
research  on  Mount  Whitney,  California,  at  an  altitude  of  14,500 
feet,  says : 

"My  conclusion  is  that  we  can  adopt  three  calories  as  the 
most  probable  value  of  the  solar  constant." 


15$  RADIANT     ENERGY. 

Nearly  as  much  hard  work  has  been  clone  to  find  this  quan- 
tity as  has  been  performed  in  finding  the  distance  of  the  sun. 
This  value  is  now  adopted  by  the  physicists  of  the  world  as  the 
most  accurate  and  comprehensive  solution  of  the  great  problem. 

A  calorie  is  the  quantity  of  heat  required  to  raise  the  tem- 
perature of  one  gram  of  water  one  degree  centigrade ;  that  is, 
if  the  earth  had  no  atmosphere,  solar  radiance  would  raise  the 
temperature  of  one  gram  of  water  three  degrees  centigrade  per 
minute  for  each  normally  exposed  square  centimeter  of  the  earth's 
surface.  The  line  A —  — B  is  one  centimeter  in  length ;  a  square 
whose  sides  are  of  this  length  would  be  a  square  centimeter, 
and  a  cube  of  the  same  width,  length  and  height  would  be  a 
cubic  centimeter.  If  the  cube  were  a  little  box  it  would  hold  just 
one  gram  of  distilled  water.  And  one  degree  centigrade  equals 
i  4-9  degrees  of  the  ordinary  Fahrenheit  thermometer.  Clearing 
of  all  metric  values  and  reducing  to  ordinary  English  numbers, 
the  quantity  of  solar  radiance  falling  on  every  square  yard  of 
the  surface  of  the  earth  at  right  angles  to  the  central  ray  of 
the  sun,  if  it  could  be  converted  into  mechanical  power  in  a 
perfect  heat  engine,  would  be  what  is  technically  known  as  slightly 
less  than  three  horse-power.  And  this  acts  continuously — the 
stupendous  flood  of  energy  since  the  appearance  of  man  on  earth 
has  not  decreased,  at  least,  within  the  period  since  the  invention 
of  stone  writing,  for  delicate  plants  now  grow  and  produce  fruit 
and  flowers  in  Egypt,  Mesopotamia  and  India  that  are  sculptured 
on  the  primeval  walls  and  pillars  of  granite  in  the  palaces  of 
Memphis,  Thebes,  Nineveh,  Ecbatana  and  Ellora,  and  whose 
fragrance  and  beauties  were  sung  by  our  primitive  and  poetic 
ancestors  round  about  the  base  of  the  Hindu  Kuh,  800  miles 
east  of  the  Caspian  sea,  B.  C.  5,000  years. 

The  climate  of  the  early  Aryans  has  not  changed — the  solar 
heat  has  been  constant  since  the  Vedic  poets  sang.  But  from 


RADIANT     ENERGY. 


that  day  until  now,  the  time  is  merely  equal  to  one  swing  of 
a  pendulum  in  cosmic  history. 

The  radiant  energy  falling  on  the  deck  of  an  ocean  liner  is 
sufficient,  if  it  could  be  utilized,  to  propel  the  ship  with  greater 
speed  than  is  now  obtained  from  carbon.  This  radiation  received 
is  upon  the  theory  that  the  earth  had  no  air.  The  air  cuts  off 
fully  one-third,  and  human  genius  so  far  is  unable  to  use  more 
than  one-eighth  of  the  remainder. 


Cut  69.    Solar  Motor,  at  the  Cawston  Ostrich  Farm,  South  Pasadena,  California. 

The  mighty  brain  of  Edison  cannot  hit  upon  a  plan  to  make 
it  more  available.  The  heat  engine  built  by  Ericsson  had  176 
square  feet,  about  20  square  yards  of  brilliant  mirror  surface  re- 
flecting the  heat  upon  a  boiler.  The  output  of  work  was  three 
horse-power,  while  about  thirty-five  horse  power  fell  on  the 
mirror. 

Cut  69  is  the  great  solar  motor  on  the  ostrich  farm  in  South 
Pasadena.  The  circular  mirror  i§  a  segment  of  a  paraboloid 


i6o  RADIANT     ENERGY. 

of  revolution,  33  feet  wide  at  the  top  and  16  at  the  bottom.  The 
property  of  this  conic  is  to  reflect  all  parallel  rays  falling  upon  it 
to  a  focus.  The  boiler  is  a  steel  tube  13  feet  long,  in  this  hot 
focus.  It  holds  100  gallons  of  water  and  space  of  6  cubic  feet 
for  steam.  The  interior  of  the  conical  surface  is  made  of  up 
1788  mirrors,  side  by  side.  The  whole  apparatus  is  hung  on  an 
axis  parallel  to  the  axis  of  the  earth,  so  it  will  follow  the  sun, 
like  an  equatorial  telescope ;  and  is  also  furnished  with  mechanism 
to  raise  and  lower  the  mirror  when  the  sun  is  north  or  south  of 
the  equator.  The  indicated  output  is  eleven  horse-power,  with 
210  pounds  of  steam,  and  it  has  pumped  water  at  a  maximum  rate 
of  1,400  gallons  per  minute.  Why  not  irrigate  the  waste  places 
of  the  earth  ? 

The  mirror  area  is  70  square  yards,  and  therefore  receives 
i3O-horse  power  of  radiation,  but  uses  eleven,  or  about  one- 
twelfth.  Since  men  appeared  on  the  planet  no  such  problem  has 
presented  itself  as  that  of  utilizing  the  eleven-twelfths  now  going 
to  waste. 

In  the  cut,  A  is  the  boiler,  and  E,  the  engine-house.  The 
radiance  of  the  sun  should  be  caught  on  countless  mirrors,  and 
the  energy  transformed  to  work.  A  million  accumulators  ought 
to  be  stored  with  the  potential  form  of  electricity  to  move  every 
wheel  on  earth  and  turn  the  darkness  of  night  into  the  light  of 
dav. 


RADIANT     ENERGY.  161 


XXIII. 

DYNAMICS    OF   THE    SUN. 

"Horns :  the  strong  bull.  Friend  of  Justice.  King  of  Upper  and 
Lower  Egypt.  Lord  of  the  periods  of  thirty  years.  Like  his  father  Ptah- 
tanen.  The  son  of  the  sun  :  Ramessu  Meri-amun.  The  sun  created  him. 
To  cause  great  rejoicing  in  the  city  of  On,  and  to  fill  with  riches  the 
sanctuaries  of  his  Creator.  Lord  of  the  two  worlds :  Ra-user-na ;  the 
chosen  one  of  the  sun :  Ramessu  Meri-amun,  the  son  of  the  sun,  who 
gives  life  of  all  stability  and  purity  today  as  ever  after." — Literal  transla- 
tion of  left-hand  face  of  the  pyramidal  apex  of  the  Egyptian  Obelisk  now 
in  Central  Park,  New  York.  Erected  by  King  Thutmes  III,  B.  C  1500 
in  the  Temple  of  the  Sun,  at  On,  Egypt. 

"Thou    sun   of   this   great   world 
Both    eye    and    soul." 
—Milton's  "Paradise  Lost,"  book  V,  line   121. 

VELOCITY   POTENTIAL,  OF   THE   SUN. 

The  distance  of  the  surface  of  the  sun  from  its  center  is 
equal  to  one,  and  from  the  sun's  center  to  the  earth  is  equal  to 
214.5.  The  square  of  I  equals  i,  and  the  square  of  214.5  equals 

45,973- 

All  radiance  proceeds  in  space  as  if  emanating  from  a  geo- 
metrical point.  And  2  7-10  multiplied  by  45,973  equals  124,127, 
therefore  the  potential  of  one  square  yard  of  the  normal  visible 
surface  of  the  sun  radiates  124,127  horse  power  all  the  time. 
Langley  showed  that  very  nearly  three  horse  power  per 


162  RADIANT     ENERGY. 

square  meter  reaches  the  earth,  and  one  square  yard  is 
less  than  a  square  meter,  so  that  the  incident  energy 
would  be  close  to  2  7-10  horse  power.  A  "horse  power" 
is  that  quantity  of  energy  that  can  raise  a  stone  weighing  33,000 
pounds  one  foot  high  in  one  minute.  This  124,973  horse  power 
is  the  energy  that  gets  through  the  solar  vapors.  How  much 
leaves  the  actual  carbon  surface  is  not  known.  But  this  quantity, 
the  residue,  is  beyond  conception  in  any  finite  mind. 

The  union  of  hydrogen  with  oxygen  develops  the  most  in- 
tense heat  known  to  be  due  to  chemical  activity. 

SOURCE  OF  THE  SUN^S   HEAT. 

The  kinetic  theory  of  matter — a  vast  science  in  itself — is 
now  fully  elaborated  and  chained  subject  to  rigid  mathematical 
law.  The  heat  potential  of  any  quantity  of  matter  in  any  con- 
dition, whether  in  gas,  liquid  or  solid,  is  known  with  precision. 

The  quantity  in  the  sun  is  known,  and  its  potential  from 
a  state  of  excessively  rare  gas  down  to  its  present  size  and 
density  can  be  computed,  and  has  been  by  many  eminent  mathe- 
maticians. It  can  be  shown  that  if  the  sun  were  made  of  pure 
hydrogen,  and  should  be  ignited  in  an  atmosphere  of  oxygen  in 
sufficient  quantity  to  unite  with  all  the  hydrogen,  that  the  heat 
of  this  awful  conflagration  would  not  keep  up  radiation  for  more 
than  3,000  years.  Geology  shows  that  the  sun  has  been  pouring 
floods  of  heat,  light  and  power  upon  the  earth  for  inconceivable 
ages. 

Whence  comes  the  energy?  It  is  clear  that  there  is  no  "fire" 
on  the  sun.  Fire  is  the  union  of  other  modes  of  matter  with 
oxygen  in  general,  yet  other  modes  unite  with  evolution  of 
heat.  But  on  the  sun  modes  are  too  hot  to  unify  and  form 
chemical  compounds.  At  present  it  is  not  likely  that  chemism 
exists  on  the  sun. 


RADIANT     ENERGY.  163 

HEAT  OF  IMPACT  ON   THE  SUN. 

If  a  mass  weighing  772  pounds  be  raised  one  foot  and  let 
fall  and  strike  a  rigid  body,  the  precise  amount  of  power  re- 
quired to  raise  it  will  be  restored  and  will  appear  as  heat,  at 
the  exact  instant  of  striking.  And  as  has  been  proven,  the 
quantity  of  heat  separated  will  be  just  enough  to  raise  the  tem- 
perature of  one  pound  of  water  one  degree  F.  But  the  heat 
appearing  in  the  fall  of  772  pounds  one  foot  is  equal  to  that 
separated  by  one  pound  falling  772  feet.  This  is  Joule's  equiva- 
lent. But  a  body  falling  772  feet  and  making  impact  on  the 
earth  has  a  velocity  at  the  instant  of  collision  of  223  feet  per 
second.  This  is  the  velocity  potential  of  the  mass  of  the  earth 
and  ranks  high  as  an  important  element  of  knowledge  in  the 
possession  of  man.  It  can  be  at  once  applied  to  the  universe  by 
well-known  mathematical  equations. 

Law :  One  pound  of  matter  in  motion  with  a  velocity  of 
223  feet  per  second  has  stored  within  it  sufficient  kinetic  energy 
to  heat  one  pound  of  water  i  degree  F. 

Now  throw  this  sounding  line  into  the  depths  of  the  sidereal 
structure.  With  this  magic  number  all  space  may  be  explored, 
and  it  can  be  at  once  computed  what  quantity  of  heat  will  be 
separated  by  the  cessation  of  motion  of  any  cosmical  mass  in 
space,  soon  as  it  is  found  how  fast  it  is  moving.  Heat  of  impact 
varies  as  the  square  of  the  velocity  of  the  colliding  body.  If  any 
mass  is  seen  in  motion,  to  find  the  heat  of  impact : 

Rule :  Multiply  the  square  of  its  velocity  in  feet  per  second 
by  the  reciprocal  of  the  square  of  223,  which  is  .00002010899. 

This  number  has  tremendous  analytical  power,  and  there  is 
no  escape  from  its  clutch  for  any  mass,  if  it  is  moving. 

If  a  mass  fall  from  an  infinite  distance  with  unimpeded 
motion,  that  is,  if  it  had  been  falling  forever,  it  would  take  for- 
ever to  fall  through  infinite  distance,  its  final  velocity  at  instant 


164  RADIANT     ENERGY. 

of  impact  on  the  earth  would  be  finite  and  would  be  6.94034 
miles,  not  quite  7  per  second.  Reduce  this  to  feet,  square  the 
number,  apply  the  rule,  and  the  result  is  27,855  degrees  F.,  or 
the  heat  (maximum)  that  can  be  separated  by  any  meteorite  or 
comet  that  may  hit  the  earth  if  it  had  no  air. 

The  gravity  potential  on  the  sun's  surface  is  27,696  times 
stronger  than  it  is  on  the  earth's  .surface,  and  its  velocity  poten- 
tial is  383  miles  per  second,  from  an  infinite  distance.  Reduce 
this  to  feet,  square  the  number,  multiDlv  the  product  by  the 
above  reciprocal,  and  the  appalling  result  is  81,154,000  degrees 
F.  liberated  by  impact  of  a  falling  body  on  the  sun,  if  the  sun's 
surface  were  rigid  and  it  had  no  atmosphere.  That  is,  if  the 
body  had  been  falling  through  an  infinite  distance  in  an  infinite 
time.  If  these  could  obtain,  the  terminal  velocity  would  be  finite, 
383  miles  per  second;  yet  might  as  well  be  infinite,  so  far  as 
the  limitations  of  the  human  mind  are  concerned. 

Go  into  space.  Twelve  million  millions  miles,  or  half  way 
to  our  nearest  neighbor,  and  again  apply  the  methematical  for- 
mula. It  is  found  that  the  velocity  with  which  a  stone  would 
strike  the  sun  falling  from  an  infinite  distance,  or  from  a  small 
finite  distance — twelve  trillion  miles — will  differ  by  not  more 
than  one  inch  per  second.  So  the  gravity  potency  of  the  sun 
lies  and  acts  almost  entirely  within  its  own  immediate  vicinity. 
The  sun  is  not  rigid  and  has  a  deep  atmosphere.  So  a  comet 
would  not  give  up  all  its  heat,  on  impact  with  the  yielding  carbon 
envelope. 

All  small  comets  would  be  dissipated  into  cosmic  dust  and 
debris  as  are  all  small  comets — meteors — that  enter  the  earth's 
atmosphere,  by  friction.  And  further,  if  the  solar  surface  were 
as  rigid  as  steel,  it  is  known  that  a  falling  body  could  not  hit 
the  sun  at  right  angles  to  a  tangent,  but  would  ricochet  like  a 
cannon  ball  on  water,  surrendering  a  part  of  its  heat  at  each 

impact.      Therefore   the   maximum   81,154,000   degrees   of   heat 


RADIANT     ENERGY.  165 

could  not  obtain.  This  was  written  in  1882  to  combat  an  alarmist 
who  wrote  that  if  the  great  comet  of  that  year  should  strike 
the  sun  the  earth  would  be  consumed.  The  terrific  heat  of  the 
sun  is  not  all  caused  by  a  hail  of  cosmical  matter  on  the  sun, 
although  no  doubt  a  minute  fraction  is,  not  more  than  one  per 
cent.  F-or  if  more  than  this  falls,  the  effect  of  the  increased 
mass  of  the  sun  would  soon  be  detected  in  the  disturbances  set 
up  in  the  orbital  motion  of  Mercury,  Venus  and  the  earth. 

The  quantity  of  matter  in  the  earth  is  known,  and  from 
known  laws  of  kinetics  and  thermo-dynamics  it  is  shown  that  if 
a  quantity  of  matter  equal  to  the  i-iooth  of  the  mass  of  the 
earth  should  rain  down  in  small  chunks  upon  the  sun  with  veloc- 
ities of  383  miles  per  second,  the  heat  of  impact  would  keep 
up  the  radiation  poured  out  by  the  sun  for  one  year.  The  earth 
could  apply  the  output  for  100  years.  But  Mercury  and  Venus 
would  be  disturbed  in  their  flights.  Some  other  and  mighty 
cause  must  be  sought — one  able  to  keep  up  the  stupendous  flow 
of  heat. 


166  RADIANT     ENERGY. 


XXIV. 
SOLAR  HEAT  POTENTIAL. 

"I  have  praised  thy  countenance,  them  creator  of  the  fullness  of  the 
earth,  Lord  of  Abydos,  who  impartest  light  to  thy  servants,  flashes  of 
light  to  the  darkness  of  night." — Egyptian  Book  of  the  Dead. 

"Driving  of   Phoebus'   chariot   Phaeton, 
Struck  by  Jove's  thunder, 
Rests  beneath  this  stone. 
He  could  not  rule  his  father's  cars  of  fire." 

—Ovid,  Met. 


"At  this  time  Tathagata,  from  the  character  which  was  on  his  breast, 
caused  to  pour  forth  a  precious  flood  of  light,  its  effulgence  like  that  of 
the  Sun,  its  rays  composed  by  a  thousand  colors,  penetrating  at  once 
through  the  infinite  worlds." — Buddha's  Teachings  to  Ananda,  Catena 
Chinese  Scriptures. 

"Mighty  power  was  concentrated  at  the  points  of  his  hands,  the  son 
of  the  sun,  Thutmes." — Glyphs  on  top  of  Obelisk,  Central  Park,  New 
York. 

HEAT  AND  GRAVITY. 

If  a  stone  weighing  one  pound  on  the  surface  of  the  earth 
be  placed  on  the  surface  of  the  sun  it  will  weigh  27.696 — almost 
28  pounds.  At  carbon  "sea  level''  on  the  sun  a  barometer  col- 
umn, instead  of  being  thirty  inches  as  on  earth,  would  be  seventy 
feet  high,  if  the  atmosphere  of  the  sun  should  be  like  that  of 
the  earth  and  of  the  same  quantity.  But  the  earth's  air,  if 
glaced  on  the  sun,  would  be  flattened  to  a  much  thinner  layer 
than  now  obtains  round  about  the  earth.  The  actual  but  to 


RADIANT     ENERGY.  167 

men  invisible  surface  of  the  sun  must  be  subjected  to  enormous 
atmospheric  pressure.  Every  square  inch  of  the  earth's  surface 
is  pressed  fifteen  pounds,  and  the  same  kind  and  quantity  of 
air  would  press  420  pounds  per  square  inch  on  the  sun. 

If  the  solar  surface  is  liquid  gas,  and  in  all  probability  it  is, 
—see  Chapter  XIV — then,  from  the  dynamics  of  liquids  it  is 
known  that  pressure  below  the  surface  varies  with  the  depth.  At 
double  depth  there  is  double  pressure.  A  place  has  been  found 
on  earth  where  the  depth  of  the  ocean  is  more  than  five  miles. 
One  cubic  foot  of  water  weighs  62^  pounds,  so  on  one  square 
foot  of  this  ocean  floor  the  pressure  is  2,000,000  pounds.  One 
average  cubic  foot  of  the  sun,  if  placed  on  the  surface  of  the 
earth,  would  weigh  88  pounds,  but  on  the  sun  it  weighs  2460 
pounds,  for  the  mean  density  of  the  sun  is  41  per  cent  greater 
than  that  of  water,  and  gravity  28  times  stronger.  So 
62^x1.41x28  equals  1,475  pounds.  How  inconceivable  the  pres- 
sure below  the  surface  and  near  the  center.  The  greater  the  pres- 
sure the  more  intense  the  heat  so  long  as  the  sun  is  a  gas,  whether 
gas  or  liquid  gas. 

The  thermal  energy  of  matter  is  known  with  great  accuracy, 
and  the  kinetic  energy — that  is  energy  of  motion — of  gaseous 
particles  is  also  known  with  precision,  and  they  are  in  the  clutch 
of  mathematical  law,  whence  there  is  no  escape. 

Helmholtz  first,  and  many  mathematicians  since,  have  many 
times  computed  the  thermo-dynamics  of  the  sun.  All  agree 
within  the  limits  of  minute  details,  that  if  the  sun  contracts  in 
diameter  nine  inches  per  day,  energy  in  the  form  of  heat  would 
be  supplied  at  its  present  rate.  The  angular  diameter  of  the  sun 
is  1,924  seconds  of  an  arc,  and  the  linear  diameter  is  866,000 
miles.  So,  one  second  equals  450  miles.  But  one  second  is 
about  as  small  a  dimension  as  can  be  seen  by  a  good  eye  in  a 
large  telescope.  With  a  contraction  of  nine  (9)  inches  per  day, 


168  RADIANT     ENERGY. 

it  would  require  9,400  years  to  contract  one  second,  an  amount 
so  small  that  it  could  be  detected  only  by  a  micrometer. 

In  Chapter  XXIII,  it  was  shown  that  if  a  body  is  moving 
with  a  speed  of  223  feet  per  second,  and  if  all  its  motion  in- 
stantly comes  to  an  end  by  its  striking  a  body  rigid  enough 
to  flatten  out  the  moving  body  into  a  very  thin  layer  of  particles 
all  at  once,  and  if  the  falling  body  weighs  one  pound,  the  heat 
liberated  will  be  enough  to  raise  the  temperature  <t>f  one  pound 
of  water  one  degree  F.  Now  it  makes  no  difference  whether  it 
falls  rapidly  or  slowly,  the  quantity  of  heat  surrendered  by  fric- 
tion against  adjacent  particles  will  be  the  same.  Hence,  the  heat 
of  the  sun  is  caused  mainly  by  friction,  and  cessation  of  motion 
of  particles  hitting  against  each  other  in  the  process  of  contraction. 

This  doctrine  is  now  adopted  by  all  the  mathematical 
physicists  of  the  world.  The  diameter  of  the  sun  was  once  full 
thirty  million  times  greater  than  it  is  now — that  is  when  ex- 
panded, in  all  directions  to  a  distance  equal  to  half  that  of  the 
sun's  nearest  neighbor.  Its  radiant  energy  was  then  all  potential. 
Each  particle  on  the  periphery  of  the  primordial  gaseous  sphere 
has  been  a  falling  body  since,  and  computation  is  able  to  deter- 
mine the  kinetic  energy  of  the  entire  mass.  For  the  mass  is  also 
known. 

When  the  diameter  of  the  sun  was  twenty-five  trillion  miles 
its  temperature  was  that  of  absolute  zero — 461  degrees  F.  Con- 
traction due  to  central  gravity  set  in  and  has  continued  until  the 
present  and  is  now  in  active  operation.  After  inconceivable 
ages,  long  heat  waves  began  to  undulate  and  after  the  lapse  of 
more  millions  of  years  short  light  waves  appeared.  The  founda- 
tion of  the  mathematics  of  solar  potential  was  laid  by  the  brain 
of  Helmholtz,  but  his  formulas  have  been  much  elaborated  since 
his  death,  notably  by  Professors  See  and  Doolittle,  with  aston- 
ishing results.  Thus,  while  the  gaseous  cosmic  sphere  contracted 
from  its  original  diameter  of  twenty-five  trillion  miles  down  to 


RADIANT     ENERGY.  i69 

the  insignificant  diameter  of  seventy-two  million  miles,  when  it 
just  filled  the  present  orbit  of  Mercury,  it  radiated  only  one 
eighty-third  of  the  energy  it  has  since  emitted.  This  vast  prob- 
lem, all  based  on  rigid  mathematics,  throws  much  light  on  the  past 
career  of  man  on  earth,  upon  the  glacial  epochs  and  other  geo- 
logical problems.  And  these  relate  to  the  future  of  men  upon 
the  earth. 


i  jo  RADIANT     ENERGY. 


TOTAL  ENERGY  OF  THE   SUN. 
XXV. 

And  sitteth  awhile  on  Greyfel 

On  the  marvelous  thing  to  gaze, 
For  lo!    the  side  of  Hindfell  enwrapped 

By  the   fervent  blaze, 
And  naught  'twixt  earth  and  heaven 

Save  a  world  of  flickering  flame, 
And  a  hurrying,  shifting  tangle, 

Where  the  dark  rents  went  and  came 

— Saga  of  the  Volsungs. 

He  opened  the  great  gates  in  the  darkness  shrouded ; 
The  fastenings  were  strong  on  the  left  and   right. 
In  its  mass  he  made  a  boiling. 
*    *    *    the  night  be  overshadowed 

*     *     *     until  the  shining  of  the  day. 

His  [the  sun's]   horns  are  breaking  through  to  shine  on  the  heavens. 
On  the  seventh  day  a  circle  he  begins  to  swell, 
And  stretches  toward  the  dawn  further,  when  the     *    *     * 

— Fifth  tablet  of  Creation  Myth,  primitive  Babylonian  script. 

HISTORY    OF   THE    SUN. 

When  our  sun  had  a  diameter  of  twenty-five  million  million 
miles,  which  it  had  when  extended  halfway  to  its  nearest  neigh- 
boring sun,  a  volume  of  it,  of  the  size  of  the  earth,  contained 
a  quantity  of  ultra-gaseous  matter  which^  if  condensed  into 
one  chunk,  and  brought  to  the  earth's  surface  and  weighed, 
would  weigh  127  pounds.  The  volume  of  the  earth  is  260  billion 
cubic  miles,  so  it  required  292,000  cubic  miles  to  contain  matter 


RADIANT     ENERGY.  777 

weighing  one  grain.  A  piece  of  brass  of  the  size  of  this  square, 
one-fortieth  of  an  inch  thick,  weighs  one  grain.  This  is 
easily  computed  for  the  sun,  planets  and  moons  in  the 
solar  system  contain  a  mass  of  two  octillion  tons,  nearly. 
The  primordial  solar  nebula  must  have  been  at  the  absolute  zero 
— 461  degrees  F.,  for  two  of  the  particles  must  either  hit  to- 
gether to  separate  heat  by  friction,  or  they  must  unite  chemically. 
But  they  could  do  neither  when  long  distances  apart,  for  every 
one  must  gravitate  toward  the  center  of  gravity  of  the  whole 
mass.  Since  a  cubic  space  inclosing  292,000  solid  miles  would 
.be  66  miles  on  each  side,  the  little  sheet  of  brass,  if  cut  into 
292,000  portions  and  equally  distributed,  would  be  one  mile  apart. 
Nothing  but  the  Thomsonian  corpuscles,  the  i-ioooth  of  the  mass 
of  the  unit  hydrogen  particle,  could  occupy  the  space.  And  they 
were  not  very  closely  packed.  The  mass  began  contraction  at 
an  exceedingly  slow  rate,  for  gravity  is  weak  at  a  distance  of 
i2J/2  trillion  miles.  All  the  heat  radiated  from  that  time  has 
been  caused,  so  far  as  science  can  now  see,  by  collisions  of  the 
particles.  For  chemical  union  cannot  take  place  in  terrific  cold 
or  heat.  Chemism  is  completely  arrested  by  the  cold  of  liquid 
air,  and  this  is  hotter  than  the  absolute  zero.  If  at  any  time 
the  temperature  of  the  subsiding  cosmical  sphere  was  such  that 
two  or  more  phases  could  change  their  rates  and  unite  into  a 
compound,  all  such  combines  have  long  since  been  broken  up 
by  the  immensely  greater  heat  of  friction  now  resident  in  the 
sun.  For  no  spectroscopist  believes  that  compounds  now  exist 
in  the  solar  globe.  It  is  far  too  hot  for  the  presence  of  either 
"fire"  or  chemism. 

The  original  gaseous  sphere  kept  on  shrinking,  each  particle 
moving  on  straight  lines,  and  gradually  nearing  each  other.  Let 
this  process  continue  for  unnumbered  eons,  until  finally  the  whole 
had  subsided  to  the  present  orbit  of  Neptune.  Its  diameter 
then  would  be  5,580,000,000  miles.  Again  computing  its  density, 


172  RADIANT     ENERGY. 

it  is  still  found  to  be  16,695,000  times  less  dense  than  the  ex- 
ceedingly rare  gas,  hydrogen. 

All  students  of  chemistry  know  how  attenuated  is  the  elusive 
hydrogen,  and  with  what  care  it  must  be  kept  from  escaping,  for 
air  is  14.44  times  more  dense.  Platinum  just  begins  to  emit  light 
when  its  temperature  is  525  degrees  C.,  and  the  carbon  filament 
in  an  incandescent  lamp  bulb  at  390  degrees,  iron  at  378  and 
gold  at  417  C.  Therefore,  when  the  sun's  periphery  reached  Nep- 
tune's distance,  it  was  yet  enshrouded  in  primeval  darkness  and 
invisible  from  space.  And  it  is  doubtful  if  its  temperature  was 
much,  if  any,  above  the  absolute  zero. 

From  expansion  of  Helmholtz'  original  formulas  of  solar 
heat  potential  from  primordial  gas  to  solid,  Dr.  See  has  com- 
puted the  entire  quantity  evolved  by  the  impact  of  all  the  particles 
in  two  octillion  tons  of  matter  and  finds  it  to  be  49,048,200  de- 
grees F.  This  is  the  heat  separated  by  contraction  from  either 
an  infinite  diameter,  or  from  a  diameter  of  only  25  trillion  miles. 
In  Chapter  XXI  it  was  shown  that  the  terminal  velocities  of  col- 
lision on  the  sun  of  a  stone  that  started  to  fall  at  an  infinite  dis- 
tance, or  from  a  distance  of  121/2  trillion  miles  would  differ  only 
by  a  fraction  of  an  inch  per  second.  And  in  these  researches 
into  heat  potential  it  is  now  found  that  if  the  original  gaseous 
mass  began  to  contract  from  an  infinite  diameter,  or  from  a 
finite  diameter  of  say  25  trillion  miles,  that  the  difference  of  the 
heat  output  is  small;  so  velocity  potentials  and  the  potential  of 
heat  agree  in  these  elaborate  analytical  investigations.  Coming 
down  to  the  Neptunian  orbit  and  again  applying  the  formulas, 
it  is  found  that  if  the  primitive  gaseous  mass  began  to  contract 
even  at  that  small  diameter,  the  quantity  of  heat  liberated  would 
be  49,040,750  degrees  F.,  only  7,250  degrees  less  than  if  it  had 
subsided  from  an  infinite  diameter,  or  a  finite  of  25  trillion  miles. 


RADIANT     ENERGY. 


XXVI. 
THE   ANCIENT   SUN. 

"So,  I  wot,  was  earth  melted  in  the  glare  of  burning  fire.  Then, 
troubled  in  spirit,  he  hurled  him  into  wide  Tartarus." — From  Hesiod 
Theogony. 

The  mysteries  of  catalysis  are  being  exploited  in  the  effect 
it  has  in  relation  to  life.  This  is  the  action  of  a  mode  of  matter 
on  other  modes  causing  them  to  unite  without  being  itself  af- 
fected. Finely  divided  platinum  is  a  catalytic  agent,  and  so 
is  a  sheet  of  platinum  if  absolutely  clean.  Thus :  alcohol  dropped 
upon  powdered  platinum  becomes  changed  to  acetic  acid,  the 
platinum  suffers  no  change  whatever,  except  becoming  heated. 
If  formic  acid  comes  in  contact  with  fine  platinum  particles,  it 
is  changed  to  carbonic  acid.  If  platinum  foil  is  put  into  a  me- 
chanical mixture  of  oxygen  and  hydrogen,  a  chemical  union 
begins,  resulting  in  the  formation  of  water.  The  platinum  be- 
comes hot;  after  the  process  is  complete  it  cools,  and  no  change 
is  noted.  The  metal  can  repeat  the  work  indefinitely,  with  no 
apparent  exertion  or  energy — and  the  mystery  is  where  the  en- 
ergy comes  from.  All  this  has  been  known  for  years  to  chem- 
ists. But  now  comes  the  bio-chemist  Loeb  of  Chicago  and  ap- 
plies this  remarkable  action  to  the  production  of  the  first  life  on 
the  inorganic  earth.  Thus  life  might  have  been  caused  by  the  mere 
presence  of  a  third  mode  of  matter.  These  promoting  agents  are 


174-  RADIANT     ENERGY. 

called  enzymes  (ferments).  Modes  besides  platinum  act  as  en- 
zymes, gold,  silver  and  others  will  thus  act.  Thus  the  enzyme,  called 
oxydane,  in  the  lungs  enables  oxygen  of  the  air  to  be  assimilated 
and  sustain  life,  while  many  other  enzymic  agents  are  found  in 
the  living  body.  He  has  apparently  shown  that  all  life  is  due  to 
the  action  of  the  enzymes.  (See  Loeb's  Columbia  College,  N.  Y., 
lecture.)  But  this  action  has  all  along  been  supposed  in  these 
notes.  Since  enzymes  suffer  no  change,  and  as  the  sum  of 
energy  in  existence  is  constant,  these  bodies  merely  direct  rad- 
iance already  saturating  space,  constantly  poured  forth  from 
countless  suns.  For  actinium  and  polonium  perpetually  direct 
waves  against  and  through  other  bodies,  being  themselves  with- 
out change. 

In  all  researches  into  the  physics  and  chemism  of  the  primi- 
tive gaseous  sphere,  catalysis  has  not  been  introduced.  This  is 
one  of  the  most  mysterious  activities  in  nature.  It  is  action  by 
influence.  Professor  Charles  E.  Munroe  (Proc.  Am.  Ass'n, 
Cleveland,  p.  119)  "finds  in  the  behavior  of  compound  radicals, 
and  in  the  change  wrought  by  the  factors  of  time,  mass  and 
temperature,  positive  evidence  of  the  effect  of  environment  and 
qualifying  conditions  in  determining  the  production  of  species." 

That  is,  chemical  union  is  in  many  cases  determined  by  what 
is  adjacent.  Applying  this  to  the  dwindling  sun  it  is  seen  that 
particles  might  approach  the  center  side  by  side  for  ages  and 
not  unite  until  a  third  particle  was  encountered  which  by  its 
mere  presence  causes  them  to  unify  without  itself  suffering  any 
change,  for  it  is  still  able  to  cause  others  to  unite  on  its  long 
flight  to  the  condensing  central  sun. 

Heat  appears  when  differing  phases  of  matter  have 
their  rates  changed  by  uniting,  or  before,  so  they  will  unite; 
and  if  the  activity  is  intense  enough,  light  radiates ;  but  in  the 
archaic  mass  neither  was  liberated  for  untold  ages  of  subsidence, 
vast  periods  of  weak  catalytic  action,  and  eons  of  rarely  oc- 


RADIANT     ENERGY.  775 

curring  collisions.  Affinity,  heat  and  light  are  late  products  of 
the  sun. 

This  theory  that  catalysis  was  the  first  mode  of  energy  that 
began  to  work  on  the  primordial  mass  is  offered  for  what  it  is 
worth,  if  anything.  For  later,  affinity  laid  hold  on  matter,  and 
wrought  ;  but  this  is  not  catalytic. 

Electro-chemism  and  polarity,  so  ably  treated  by  Berzelius, 
Faraday  and  Ampere,  most  fascinating  subjects,  must  be  omitted. 
As  soon  as  two  corpuscles  united  by  the  mere  influence  of  a  cata- 
lyst they  became  centers  of  increased  activity,  but  they  all  fell 
toward  the  forming  sun  in  the  center. 

After  great  subsidence,  through  vast  periods  of  time,  the 
sun  became  smaller,  with  liberations  due  to  increased  collisions, 
of  heat  and  then  light,  succeeded  or  preceded  by  electricity,  elctro- 
magentism  and  polarization. 

All  phases  of  energy  appear  now  in  the  still  condensing  sun. 
The  monads  of  Liebnitz,  pantogen  of  Hinrichs,  protyle  of  Crooke's; 
vortex  rings  of  Kelvin,  atoms  of  Aristotle  and  Lucretius  and 
every  other  concept,  ancient  or  modern,  are  comprehended  and 
included  in  Thomson's  corpuscles  and  Crooke's  electrons  —  '"bodies 
smaller  than  atoms."  These  fill  every  requirement  made  by 
physicists  and  mathematicians  of  all  ages  in  striving  to  account 
for  the  successive  evolutions  through  which  all  matter  must  pass. 

Catalytic  force  is  ''that  substances  by  their  mere  presence, 
and  not  by  their  affinity,  have  the  power  to  rouse  latent  affinities, 
so  that  compound  substances  undergo  reaction  and  a  greater 
electro-chemical  neutralization  occurs."  —  Berzelius. 

"A  catalyst  is  any  substance  which  alters  the  velocity  of  a 
chemical  reaction  without  appearing  in  the  final  product."  "There 
seems  to  be  no  kind  of  chemical  reaction  which  cannot  be  cata- 
lytically  influenced,  and  no  chemical  substances,  whether  elements 
or  compounds,  which  cannot  act  catalytically." 

"The  presence  of  hydrogen  ions  accelerates  most  chemical  re- 


776  RADIANT     BNBRGY. 

actions,  so  they  must  be  regarded  as  catalysts  of  great  gener- 
ality; and  there  are  especially  among  the  enzymes,  specific  cata- 
lysts which  only  exert  their  accelerating  action  on  perfectly 
definite  substances." 

"We  have  three  different  means  of  influencing  the  velocity 
of  chemical  reactions :  temperature,  concentration  and  catalysis." 

"Oxidation  of  napthalum  by  means  of  sulphuric  acid  with 
speed,  can  only  be  brought  about  in  the  presence  of  mercury." 
"A  trace  of  gas  may  cause  the  liberation  of  an  entirely  dispro- 
portionate amount  of  another  gas." 

There  are  four  phases  of  catalytic  activity  known:  First, 
release  in  supersaturated  systems ;  second,  catalysis  in  homeo- 
geneous  mixtures ;  third,  catalysis  in  heterogeneous  mixtures ; 
fourth,  enzyme  action.  (Professor  Oswald,  "Nature,"  April  3, 
1902.) 

If  the  hypothesis  of  primeval  catalytic  action  is  accepted, 
then  a  host  of  difficulties  that  have  so  long  troubled  physicists 
and  chemists  in  accounting  for  the  successive  steps  in  the  evolu- 
tion of  the  sun  will  vanish.  For  corpuscles  are  known  to  be 
surrounded  by  a  field,  for  a  long  time  called  "sphere"  of  action. 
Thus  heat  and  light  are  recent;  the  sun  has  been  invisible  until 
lately.  But  electricity  may  not  be  merely  a  late  worker,  for  in- 
deed it  may  be  the  primordial  catalyst. 


RADIANT     ENERGY.  777 


XXVII. 
THE  RADIANT  SUN. 

"After  having  produced  the  universe,  He,  whose  power  is  incom- 
prehensible, vanished,  again  absorbed  in  the  supreme  soul." — Laws  of 
Manu,  Bk.  L,  Shloka  50,  Archaic  Hindu  Phil. 

Professor  Langley  has  shown  that  of  the  total  amount  of 
radiation  from  the  sun,  19  per  cent  is  in  the  visible 
portion  of  the  spectrum.  There  is  but  one  kind  of 
energy  radiated  from  the  sun — the  light,  heat  and  chemical 
effects  depend  entirely  upon  the  state  or  condition  of  the  matter 
upon  which  the  differing  wave  lengths  may  happen  to  fall.  Here 
is  a  quotation  from  one  of  the  most  eminent  physicists  which  the 
world  has  ever  seen : 

"Up  to  1872  it  was  almost  universally  believed  that  there 
were  three  different  kinds  of  entities,  actinic,  luminous  and  ther- 
mal, represented  in  the  spectrum.  There  is  one  radiant  energy 
which  appears  to  us  as  'actinic/  or  'luminous,'  or  'thermal'  radia- 
tion, according  to  the  way  we  observe  it.  Heat  and  light,  then, 
are  not  things  in  themselves,  but  different  sensations  in  our  own 
bodies,  or  different  effects  in  other  bodies,  are  merely  effects 
of  this  mysterious  thing  we  call  radiant  energy." — S.  P.  Langley, 
Proc.  American  Association  Science,  Cleveland  session. 

The  Italian  physicist  Melloni  says :  "Light  is  merely  a  series 
of  calorific  indications  sensible  to  the  organs  of  sight,  or  vice 
versa,  the  radiations  of  obscure  heat  are  veritable  invisible  radia- 
tions of  light." 


RADIANT     ENERGY. 

Melloni  wrote  this  nearly  sixty  years  ago,  in  1843,  but  it 
was  not  adopted  until  Langley  by  his  elaborate  researches,  more 
refined  and  complex  than  all  preceding,  proved  it.  The  doctrine 
of  one  radiant  energy  is  now  adopted  by  the  great  physicists  of 
the  world.  It  only  remains  now  for  them  to  say  there  is  only 
one  matter. 

From  Helmholtz'  formulas  it  has  been  shown  that  if  the 
sun,  whose  mass  is  two  octillion  tons,  contracted  from  an  infinite 
diameter  to  a  diameter  down  to  the  present  diameter  of  the  orbit 
of  Neptune,  the  total  heat  separated  by  friction  and  collisions 
of  its  particles,  was  sufficient  to  raise  the  temperature  of  two 
octillion  tons  of  water  7,202  degrees  F.  When  it  collapsed  to 
the  present  distance  of  Jupiter — diameter  one  billion  miles — the 
heat  liberated  would  heat  two  octillion  tons  of  water  43,960  de- 
grees F.  and  that  contracting  from  an  infinite  diameter  or  from 
a  finite  diameter  of  twenty-five  trillion  miles  down  to  its  present 
diameter  866,000  miles,  the  heat  sent  into  space  has  been  suffi- 
cient to  heat  two  octillion  tons  of  water  to  a  temperature  of 
49,050,000  degrees  F.  For  it  is  known  just  how  much  work  would 
be  done,  if  one  carried  a  ton  of  matter  away  from  the  sun  to 
twelve  and  one-half  trillion  miles,  or  to  any  distance  even  to 
infinity. 

To  the  non-mathematical  reader  it  is  well  to  state  that  when 
a  formula  is  applied,  at  varying  distances,  rates,  pressures,  etc., 
they  often  run  out  toward  the  infinitely  small  or  infinitely  large. 
Since  the  law  of  variation  of  the  formula  in  question  is  known, 
it  is  also  known  with  unerring  accuracy  when  the  formula  will 
come  to  an  end. 

And  the  work  done  in  carrying  a  mass  away  from  the  sun — 
that  is,  work  of  lifting  the  mass — as  a  stone  is  lifted  on  the 
earth — is  equal  to  the  work  of  drawing  it  in  from  space.  Thus 
the  gravity  potential  at  any  distance  from  the  sun  is  easily  com- 
puted, and  from  thermodynamic  laws,  the  heat  equivalent  of  work 


RADIANT     ENERGY.  i79 

is  known.  The  heat  equations  have  been  solved  on  the  hypothesis 
that  the  sun  in  the  long  period  of  its  subsidence  was  homogen- 
eous throughout — and  the  vast  quantities  of  heat  seem  large 
enough.  But  Anne  Sewell  Young  of  the  University  of  Chicago 
made  computation  with  the  formulas  of  Helmholtz  on  the  theory 
that  the  sun  was  all  the  time  more  dense  in  the  center  and  there- 
fore the  entire  mass  was  not  homogeneous.  And  she  proved  that 
if  it  were  denser  in  the  central  portions,  the  heat  would  be 
greater !  But  the  mighty  power  of  the  sun  is  exerted  in  space 
near  it.  For  if  the  sun  contracted  from  a  diameter  of  twenty- 
five  trillion  miles,  or  began  to  contract  at  a  diameter  equal  to 
that  of  the  earth's  orbit,  or  186,000,000  miles,  the  heat  output 
would  have  been  48,819,600  degrees  F.,  which,  subtracted  from 
49,050,000  degrees,  equals  231,000  degrees,  or  only  1-21 5th  part, 
was  radiated  from  the  beginning  of  contraction  until  it  dwindled 
down  to  the  insignificant  diameter  of  the  orbit  of  the  earth. 
Therefore,  when  the  periphery  of  the  shrinking  sun  was  passing 
the  earth's  orbit,  it  was  beyond  a  doubt  invisible  from  space, 
from  any  light  due  to  rapid  rates  caused  by  heat.  Computing 
again  at  the  orbit  of  Mercury,  i-83d  of  the  heat  was  poured 
into  space  since  it  began  to  contract.  Make  the  sun  twice 
its  present  diameter  and  again  apply  the  formula,  and  the 
result  is  that  in  subsiding  to  that  small  diameter,  it  lost 
only  half  its  heat.  The  best  estimates  of  physicists  are  that  the 
sun  is  radiating  heat  enough  to  reduce  its  temperature  2^/4  degrees 
per  year,  and  49,050,000  divided  by  this  gives  21,800,000  years 
as  the  life  of  the  sun.  Helmholtz  made  it  22,000,000  years.  New- 
comb  says  not  much  above  20,000,000,  but  no  mathematician  com- 
putes more  than  22,000,000  years.  It  is  considered  that  it  has 
been  radiating  heat  18,000,000  years  and  has  4,000,000  yet  to 
run  its  mighty  furnace. 

All  these  deductions   are  made  on  the  assumption  that  all 
the  heat  has  been  caused  by  contraction.    But  chemism  must  have 


180  RADIANT     ENERGY. 

produced  some,  and  the  fall  of  meteors  and  comets  a  fraction 
more.  But  whatever  heat  was  formed  by  chemical  union  has 
surely  been  counteracted  by  the  work  done  since  in  dissociation, 
for  none  hold  that  there  are  compounds  now  withstanding  the 
terrific  heat.  So  the  times  given  are  probably  not  far  from  the 
truth. 

STEFAN'S  LAW. 

''Radiation  varies  as  the  fourth  power  of  the  temperature." 
This  is  an  important  law,  for  heat  an  iron   1,500  degrees 
and  measure  its  rate  of  radiation ;  then  heat  it  to  3^000  degrees 
and  measure  again ;  the  radiation  will  be  sixteen  times  as  rapid, 
for  sixteen  is  the  fourth  power  of  two. 

Thus,  if  the  sun  ever  gets  to  be  twice  as  hot  as  now,  the 
radiation  will  be  sixteen  times  as  intense  and  destroy  all  living 
beings  on  Mercury,  Venus,  the  earth  and  Mars,  if  at  that  time 
the  quantity  would  be  sufficient.  This  is,  however,  a  mere  specu- 
lation, for  if  the  rate  of  radiation  should  double,  it  is  likely  that 
the  sun  would  be  much  smaller  than  now,  with  far  less  surface, 
and  the  quantity  of  heat  much  less,  although  more  intense.  For 
one  can  stand  near  an  arc  light  heated  to  several  thousand  de- 
grees, with  the  most  intense  radiation,  while  it  would  be  impos- 
sible to  stand  anywhere  near  a  large  stove  heated  to  the  same 
temperature.  From  Stefan's  law  it  is  seen  that  if  the  sun  has 
ever  varied  its  temperature  much,  the  rate  of  radiation  has 
changed  violently.  These  fluctuations  would  have  marked  effect 
on  the  geological  career  of  the  earth. 

LANE'S  LAW. 

An  American  mathematician,  Mr.  J.  Homer  Lane,  discovered 
by  analytics  a  most  remarkable  law  of  radiation. 

Law :  "A  gaseous  sphere,  losing  heat,  under  its  own  gravity, 
must  become  hotter  until  it  ceases  to  be  a  perfect  gas." 


RADIANT    ENERGY.  /<?/ 

Here  are  values,  if  the  sphere  contracts  to  half  the  diameter: 

Gravity  on  its  surface  equals 4 

Surface  with  half  the  diameter  equals y^ 

Pressure  on  one-fourth  the  surface  equals.  ...    16 

Density  of  the  smaller  sphere  equals 8 

Volume  of  the  smaller  sphere  equals l/% 

Heat  of  the  smaller  sphere  equals 2 

The  quantity  of  heat  will  actually  be  doubled  and  the  rate 
of  its  radiation  will  be  sixteen  times  as  rapid;  that  is,  if  repul- 
sion of  heat  and  attraction  of  gravity  were  equal  when  the  diam- 
eter of  the  sphere  was  one,  then,  when  the  diameter  shrinks  to 
one-half,  the  heat  must  be  doubled  to  still  keep  the  surface  in 
equilibrium.  So  soon  as  the  sphere  becomes  liquid,  Lane's  law 
no  longer  acts.  But  the  sun  is  a  gas  and  may  become  very  much 
hotter  in  future  ages. 

If  the  entire  sun  should  be  instantly  covered  by  ice  fifty 
feet  deep,  it  would  all  be  melted  in  one  minute. 

To  keep  up  the  sun's  present  output  of  heat  by  means  of 
fire  would  require  a  layer  of  anthracite  coal  eighteen  feet  thick 
to  be  burned  every  hour. 

The  heat  received  on  each  square  foot  of  the  earth's  surface 
in  one  year,  if  changed  to  work  without  loss,  would  lift  sixty 
tons  one  mile  high. 

Langley  compared  the  heat  radiated  from  liquid  steel  in  a 
Bessemer  converter  with  the  heat  from  the  sun  in  the  same 
instrument  at  the  same  time.  The  heat  from  the  sun  was  eighty- 
seven  times  more  intense  than  from  the  melted  steel ! 

No  lens  can  increase  the  intensity  of  the  apparent  heat  of 
the  sun  ;  it  simply  brings  the  sun  to  a  distance  equal  to  its  magnify- 
ing power.     One  has  been  made  that  brought  the  sun  to  an  ap- 
parent distance  of  240,000  miles — the  distance  of  the  moon.   Any- 
thing on  earth  was  turned  to  gas  when  placed  in  the  focus,  whence 
it  follows  that  if  the  earth  should  get  within  240,000  miles  of 
the  sun  it  would  be  turned  to  gas  also. 


182  RADIANT     ENERGY. 


XXVIII. 
THE   SPECTRO-BOLOMETER. 

"How  impossible  to  exhibit  in  words  the  infinite  portions  of  the 
mysterious  universe!  Each  single  atom  evolved  from  all  the  atoms,  each 
atom  evolved  from  the  aggregate  of  all.  Revolving  thus  unhindered  they 
unite  in  one  harmonious  whole." — Liturgy  of  Kwan-Yin,  Buddhistic,  Chi- 
nese service. 

A   threefold   measure   dwells   in   space — 
Restless  length,  with  flying  race; 
Stretching  forward,   never   endeth, 
Ever  widening,  breadth  extendeth 
Ever  groundless,  depth  descendeth. 

— Schiller  in  Sentences  of  Confucius. 

Shine  out,   fair   sun   till   I  have  bought  a  glass, 
That  I  may  see  my  shadow  as  I  pass. 

— "Richard  III,"  act  I,  scene  2. 

LANGI^EY'S  BOLOMETRIC  SPECTRUM. 

Before  entering  upon  a  study  of  the  stars  it  is  necessary 
to  completely  understand  the  elaborate  researches  of  Professor 
S.  P.  Langley  in  hitherto  unknown  radiations  at  each  end  of 
the  visible  spectrum.  He  discovered  waves  far  beyond  the  red 
and  violet,  and  surpassed  all  other  previous  phvsicists  in  the  deli- 
cacy of  his  determinations.  So  far  in  this  series  less  than  one 
octave  of  vibrations  has  been  treated.  For  if  a  tuning  fork  beats 


RADIANT     BNBRGY.  183 

256  times  per  second  and  another  512,  the  sound  will  be  raised 
one  octave  in  pitch,  because  512  is  twice  256.  The  longest  wave 
of  light  in  the  extreme  red  vibrates  395  trillion  times  per  second, 
and  the  shortest  violet  764  trillion.  This  is  not  an  octave,  for 
twice  395  equals  790.  Therefore  any  rate  greater  or  less  will  not 
appear  as  light,  and  the  visible  part  of  the  sun's  radiance  is  only 
a  small  fraction  of  the  output. 

If  a  metal  wire  is  carrying  a  current  of  electricity  and  the 
wire  be  heated  by  any  external  means,  the  resistance  is  increased 
and  less  electricity  flows,  and  if  cooled  the  resistance  is  dimin- 
ished and  more  current  passes.  This  is  an  important  law  in  elec- 
trical conductivity,  and  is  the  principle  upon  which  the  bolometer 
is  made.  Thus  it  is  now  believed  that  if  a  wire  of  absolutely  pure 
metal  could  be  cooled  to  the  absolute  zero,  it  would  offer  no  re- 
sistance to  electricity.  The  essential  part  of  a  bolometer  is  the 
excessively  thin  platinum  thread  or  filament,  called  the  nerve  of 
the  instrument.  It  is  hundreds  of  times  more  sensitive  to  heat 
than  any  nerve  in  the  human  body.  Here  are  the  details  of  Pro- 
fessor Langley's  most  perfect  instrument : 

Length  of  platinum  fiber,  Y^  inch;  width  of  platinum  fiber, 
i-5ooth  inch  ;  thickness  of  platinum  fiber,  i-25,oooth  inch. 

When  this  is  moved  along  in  the  spectrum  beyond  the  red 
it  detects  waves  invisible  in  any  apparatus,  and  also  detects  cold 
regions — that  is,  vacant  spaces  corresponding  to  the  black  Fraun- 
hofer  lines  in  the  visible  spectrum.  Thus  cold — i.  e.,  absence  of 
heat  waves — is  comparable  to  darkness,  absence  of  light  waves. 

This  could  not  be  done  were  it  not  for  the  law  of  variation 
of  the  current  by  heat.  The  records  and  maps  of  the  infra  red 
region  are  made  by  a  most  delicate  galvanometer,  which  must 
now  be  explained. 

Law  XVIII,  chapter  XVIII — A  magnet  free  to  move  will 
make  an  angle  with  a  current  of  electricity. 


184.  RADIANT     ENERGY. 

Cut  70  represents  a  magnetic  needle  N  S  balanced  on  the 
sharp  point  of  the  upright,  and  A  13  is  a  wire.  Send  electricity 
through  the  wire  and  the  needle  will  swing  from  the  direction 
N  S  to  the  new  direction  I  2,  making  an  angle  with  the  wire, 
and  the  size  of  the  angle  depends  on  the  strength  of  the  current. 


Cut  70.     Deflection  of  a  Magnet  by  a  Current  of  Electricity. 

But  the  long  heat  waves  beyond  the  red  make  weak  currents,  not 
able  to  deflect  the  magnet  enough  for  the  angle  to  be  measured 
accurately.  So  currents  are  strengthened,  increasing  the  number 
of  turns  of  wire  by  rolling  into  a  coil. 


Cut  71.    Suspended  Needle  With  Increased  Deflection. 

This  is  made  clear  in  cut  71,  where  a  b  is  one  turn  of  wire 
round  the  needle.  Several  hundred  turns,  side  by  side,  would  con- 
stitute a  coil  of  great  multiplying  power.  That  is,  parts  of  wire 
both  above  and  below  the  needle  act.  The  current  in  the  upper 
wire  a,  is  aided  by  that  in  wire  b,  and  makes  a  stronger  electro- 
magnetic field  within  the  space  inclosed  by  the  wire. 

In  cut  72  is  shown  the  turns  of  the  wire  in  two  coils.  Above 
them  is  a  thin  disc  ruled  to  degrees  and  minutes,  and  above  that 


RADIANT     ENERGY. 


'85 


the  needle,  exactly  above  another,  whose  end  is  seen  within  the 
field  of  the  coils.  They  are  connected  so  the  upper  turns  precisely 
as  the  lower,  and  both  are  suspended  by  a  fiber  of  silk,  and  the 
whole  delicate  apparatus  is  kept  under  a  glass  to  protect  it  from 
currents  of  air.  When  a  current  of  electricity  passes  through  the 
coils,  the  needle  turns  and  the  strength  can  be  determined  by 


Cut  72.     Galvanometer.     The  Coil  of  Wire  is  Under  the  Plate  and  Needle. 

reading  the  scale.  It  is  very  sensitive  and  has  been  used  since 
Oersted  discovered  its  law  in  1819.  But  so  refined  were  Lang- 
leys'  researches  that  it  could  not  be  used,  for  far  beyond  the  red, 
the  heat  was  not  strong  enough  to  vary  the  resistance  of  the  plati- 
num nerve  sufficient  to  vary  the  needle. 

So  a  new  form  of  galvanometer  was  devised,  whose  every 
principle  is  shown  in  cut  73,  a  d'Arsonval,  not  having  a  diagram 
of  Langley's.  This  has  no  needle,  its  place  being  taken  by  an  ex- 
tremely small  mirror  at  i.  Its  field  is  supplied  by  the  poles  of  a 
U  permanent  magnet  and  a  rectangular  coil  inclosing  a  cylinder  of 


1 36 


RADIANT     ENERGY. 


thin  iron  is  suspended  between.  The  coil  acts  as  does  a  needle 
when  the  current  is  passed  and  turns  and  the  mirror  with  it.  In 
a  dark  chamber,  a,  is  a  minute  incandescent  lamp,  whose  light 
falls  on  the  mirror.  In  a  box,  b,  the  light  strikes  a  long  sensitive 
film,  like  a  biograph  film,  which  is  rolled  from  one  spool  to  an- 
other, as  shown,  by  a  clock  which  does  not  appear.  The  film  can 
be  placed  as  far  as  required,  so  that  if  the  mirror  rotates  only 
the  i-ioooth  of  an  inch,  its  reflected  ray  may  be  made  to  trace 
an  entire  inch  on  the  film — and  thus  a  minute  motion  invisible  to 


Cut  73.     Mirror  Galvanometer  With  Graphic  Recording  Apparatus. 

the  eye  is  made  visible  and  recorded  when  the  graph  is  developed. 
The  result  is  that  when  the  bolometer  nerve  is  struck  by  a  heat 
wave  in  the  spectrum,  the  mirror  moves  and  makes  a  record  on  the 
film.  And  when  a  cold  place  is  passed  by  the  nerve  the  clock 
draws  the  film  along,  so  that  the  tiny  point  of  light  is  deflected  the 
other  way,  thus  one-one  hundred  millionth  of  a  degree  is  meas- 
ured. When  the  sensitive  galvanometer  was  made,  it  had  to  be 
put  in  a  room  inside  of  another  room  to  avoid  changes  in  tem- 


RADIANT     ENERGY. 


'$7 


perature,  and  the  temperature  was  kept  constant  automatically  by 
heating  and  cooling  coils,  so  that  the  variation  was  only  one-tenth 
of  a  degree. 

And  when  it  was  tried  to  explore  farther  and  farther  into 
the  long  weak  heat  wave  region,  it  was  soon  found  that  glass 
prisms  absorbed  the  faint  heat,  so  prisms  made  of  rock-salt  were 
used,  for  this  substance  allows  more  heat  to  pass  than  any  other 
known. 


Cut  74.    L,angley's  Spectro-Bolometer, 


The  reader  will  understand  that  the  reason  why  the  mirror 
moves  is  the  variation  in  the  strength  of  the  current  of  electricity 
flowing  in  the  coil  between  the  poles  of  the  upright  magnet  in  cut 
73,  and  the  variations  in  the  strength  of  the  current  are  caused  by 
increased  or  decreased  resistance  in  the  platinum  nerve  caused  by 
heat  and  cold  spaces  in  the  infra-red  spectrum  of  the  sun. 

Not  having  a  cut  of  Langley's  latest  bolometer,  cut  74  is  sent, 
of  a  bolometer  with  which  he  made  many  discoveries. 


iB8  RADIANT     ENERGY. 

Fig.  I  is  collimator  of  spectroscope.  The  rock  salt  prism  is 
shown  to  the  right  of  3.  Radiance  from  the  sun  comes  through 
the  tube  i,  passes  through  the  prism  of  60  degrees  angle,  which 
disperses  the  heat  waves  into  a  long  invisible  spectrum  beyond  the 
red.  It  falls  upon  the  reflector  2,  and  is  reflected  into  the  end 
of  the  bolometer,  3,  and  falls  on  the  little  platinum  fiber,  which 
crosses  it  within.  The  mirror,  2,  is  turned  so  the  thermal  spectrum 
passes  in  review  from  end  to  end,  and  every  portion  is  examined. 
Fig.  4  is  a  battery  and  5,  the  outline  of  the  galvanometer.  Fig. 
6  is  an  outline  of  what  is  inside  the  tube  3,  showing  the  nerve 
and  wires  that  connect  to  battery.  It  is  placed  in  tube  to  protect 
fiber  from  any  heat  but  that  from  the  spectrum. 

Professor  Langley's  new  bolometer,  with  which  he  made  his 
latest  researches,  is  the  most  sensitive  instrument  ever  constructed. 
Its  achievements  have  crowned  with  success  twenty  years  of  the 
most  arduous  labor,  where  human  skill  is  taxed  to  its  utmost. 

Cut  75  is  that  of  the  long  infra-red  or  new  spectrum  just  pub- 
lished— Smithsonian  Report  1900 — by  the  now  world-honored 
Professor  S.  P.  Langley.  It  is  thirteen  times  longer  than  the 
spectrum  which  makes  impress  on  the  eye.  The  wide  dark  bands 
are  mysterious.  Their  cause  is  unknown — that  is,  what  modes 
of  matter  absorbed  them — for  of  course  absorption  is  the  real 
cause  of  all  dark  and  cold  spaces  in  the  solar  spectrum.  And  now 
all  the  spectroscopists  of  the  world  will  make  experiment  on  metals 
to  find  which  absorbs,  so  as  to  produce  the  bands.  Vast  addi- 
tions to  the  sum  of  knowledge  has  been  made  by  Langley  in 
these  long-continued  and  refined  researches.  The  ultra-violet  re- 
gion, to  the  left  of  the  visible  spectrum  is  not  shown  in  cut  75. 
For  if  it  were :  "It  would  take  nearly  a  hundred  feet  of  map 
to  depict  it  on  the  prismatic  scale,  though  this  is  caused  by  but 
a  small  fraction  of  the  sun's  energy,  so  monstrous  is  the  exag- 
geration clue  to  the  dispersion  of  the  prism.  It  really  contains 
much  less  than  the  one-hundredth  part  of  the  total  solar  energy 


RADIANT     ENERGY. 


789 


Cut  75.     Professor  Ivangley's  Infra  Red,  or  Thermal  Spectrum.     The  Strips  Should 
be  Placed  Knd  to  Kad. 


I9o  RADIANT     ENERGY. 

which  exists,  the  visible  spectrum  containing  perhaps  one-fifth 
the  energy  of  the  sun." — Langley,  p.  684,  Smithsonian  Report, 
1900,  Thus  the  length  of  the  spectrum  beyond  the  violet  is  still 
unknown — depending  entirely  on  the  most  sensitive  graphic  plates. 
For  the  waves  out  there  cannot  be  detected  by  any  other  means 
than  by  graphs,  or  their  fluorescing  properties.  Their  lengths  are 
known  to  be  exceedingly  short,  and  it  is  highly  probable  that  they 
continue  to  become  shorter  until  they  become  electro-magnetic 
Roentgen  waves.  A  new  world  to  be  explored  is  opened  here  for 
all  discoveries  are  "pointing  the  way  to  future  knowledge  of  the 
connection  of  terrestrial  life  with  that  physical  creator  of  all 
life,  the  sun." — Langley,  p.  683.  Thus  calling  the  length  of  the 
light  spectrum  I,  that  of  the  heat  spectrum  is  13,  and  of  the 
chemical,  at  present  unknown.  So  that  now  the  spectrum  known 
to  Newton,  Brewster,  Wollaston,  Kirchhoff,  Fraunhofer,  Bunsen, 
and  all  early  students,  scarcely  bears  resemblance  to  the  wonderful 
map  just  given  to  an  expectant  world  by  that  tireless  worker, 
Langley. 

The  problem  of  all  ages  is  now  to  either  lengthen  them  for 
use  of  man  or  find  some  way  to  cut  them  out  of  space  and  make 
use  of  them  as  they  are. 

v  r 


Cut  76.     Langley's  Holograph.     The  Visible  Spectrum  From  V  to  R 
is  That  Known  Before 


The  energy  of  the  sun  is  irregular  in  its  distribution. 
The  thermal  waves  have  varying  intensities  out  to  the  extreme 
limit.  The  lines  and  bands  detected  by  the  bolometer  nerve  vary 
as  much  in  width  as  the  dark  lines  in  the  light  spectrum.  For 
cold  in  the  bolometer  spectrum  corresponds  to  darkness  in  the 
yisible.  It  is  difficult  to  secure  a  holograph  ;  that  is,  to  get  an  im- 


RADIANT     ENERGY.  igi 

pression  on  plates  of  the  thermal  region.  These  long,  slow  waves 
are  not  suitable  for  graphic  work.  Indeed,  the  waves  perpetually 
issuing  from  radium  are  more  powerful  and  print  a  stronger 
graph  on  the  same  sensitive  plate. 

IvANGI/EY's    LATE    DETERMINATION    OF    ENERGY    IN    THE    SPECTRUM. 

Ultra  violet  region  contains i-iooth 

Visible   iQ-iooths 

Thermal  beyond  the  red 8o-iooths 


Total   equals 


But  the  visible  contains  much  heat,  so  the  energy  called  light 
is  exceedingly  small. 


i<?2  RADIANT     ENERGY. 


PART    III. 

XXIX. 

THE   STARS. 

I  look   down  through  that  oval   ring  of  stars, 
And  see  the   far  off  earth,  a  trembling  speck, 
Dust-mote,  whirled  up  from  the  chariot  wheels  of  the  sun, 
And  pity  their  small  hearts  that  hold  a  man. 

— Sill's  Semele. 

And  the  ray-crowned  Balder  said, 

Far  to   the   south,   beyond   the  blue  there   spreads 

Another   heaven,    the   boundless, 

No  man  yet  hath  reached  it. 

Matthew  Arnold,  Balder  Dead. 

THE   STARS. 

The  word  stars  should  not  be  used  in  scientific  literature; 
it  has  no  meaning.  All  stars  are  colossal  suns  at  terrific  heats. 

All  celestial  objects  ever  seen  by  the  unaided  eye  of  man  since 
his  appearance  on  the  earth,  except  the  moon,  Mercury,  Venus, 
Mars,  Jupiter,  Saturn,  comets  and  meteors,  are  suns.  And  that 
marvel  of  all  ages — the  spectroscope — proves  them  all  to  be  simi- 
lar to  our  own  sun,  in  composition  and  temperature.  Stellar  as- 
tronomy is  a  new  science,  and  its  more  refined  departments  are 
scarcely  more  than  ten  years  old.  It  is  now  being  studied  with 
feverish  intensity,  and  the  hours  of  night  are  not  long  enough. 
Costly  spectro-photographic  apparatus  and  elaborate  measuring 
instruments  are  being  installed  in  all  the  great  observatories ;  me- 


RADIANT     ENERGY. 


chanism  that  can  weigh  a  hair  1-4  inch  in  length,  measure  the  di- 
ameter of  a  spider's  web,  detect  the  1-10,000,000  degree  of  heat 
and  measure  the  1-250,000,000  of  an  inch  in  terms  of  lengths  of 
waves  of  light. 

When  the  astronomers  of  the  seventeenth  century  began  to 
realize  the  actual  distance  of  even  the  nearest  star,  the  mere 
thought  of  it  was  simply  stupefying,  crushing  and  depressing  to 
the  spirit  of  man.  An  awful  feeling  of  insignificance  came  steal- 
ing over  the  minds  of  the  early  astronomers,  and  they  merely  had 
a  glimpse  of  the  incredible  wastes  of  space  now  known. 

The  nearest  neighbor  the  sun — our  sun — has,  is  distant  25 
million  million  miles  (25,000,000,000,000  miles).  Or,  in  short,  25 
trillion  miles. 


Cut  77.     Diagram  Showing  Distance  of  the  Sun's  Nearest  Neighbor. 

In  cut  77  &  futile  effort  is  made  to  convey  some  impression  of 
this  stupendous  distance. 

Let  the  straight  line  I,  3,  be  a  railway,  and  i,  2  and  3  sta- 
tions, while  4  is  a  distant  house  at  right  angles  to  an  observer  at 
a  car  window,  when  the  train  is  at  i.  Let  it  move  to  2,  and  the 
observer  may  see  the  house,  by  moving  the  eyes,  only,  but  on 
arrival  at  3,  not  only  the  eyes,  but  the  head  must  be  turned.  Let 
I  be  the  earth  today,  2,  the  sun,  and  3,  the  place  of  the  earth  in 


194  RADIANT     ENERGY. 

six  months;  the  distance  from  i  to  2,  being  93,000,000  miles. 
When  at  I,  let  a  person  get  the  eyes  centered  on  the  nearest  star 
in  direction  i,  4.  Then  so  the  observer  shall  not  move  his  eyes 
to  the  distance  of  the  i-ioo,oooth  of  an  inch  for  six  months,  let 
him  be  instantly  turned  to  stone,  and  at  the  end  of  the  half  year 
be  as  suddenly  restored  to  life,  and  open  the  stony  eyes,  when 
lo !  the  star  is  in  the  center  of  the  eye  still — that  is,  the  displace- 
ment of  the  earth  186,000,000  miles  has  no  effect  that  can  be  de- 
tected by  the  eye,  for  it  sees  the  distant  star  in  direction  3,  5,  ex- 
actly as  from  i  to  4,  the  cardinal  fact  standing  out  that  the  lines 
i,  4  and  3,  5  are  parallel. 

ASTRONOMERS'  EARLY  STRUGGLES. 

If  at  3,  his  train  should  turn  and  go  on  a  straight  line  to 
the  nearest  star,  incessantly  with  a  speed  of  one  mile  per  minute,  it 
would  require  a  time  of  47,528,800  years  to  traverse  the  mighty 
void. 

In  1530  Copernicus  taught  that  the  earth  moved  around  the 
sun,  and  not  the  sun  about  the  earth,  as  had  been  held  since  the 
end  of  Egyptian  astronomy.  Soon  as  he  expounded  the  doctrine, 
astronomers  and  mathematicians,  the  few  that  then  lived,  ac- 
cepted it.  At  once,  the  combined  power  of  Europe  was  raised 
as  a  barrier  against  them.  For  the  unanswerable  argument  was 
raised  that  if  the  earth  moved  from  one  side  of  a  vast  orbit  to  the 
other,  the  stars  must  be  displaced  in  the  opposite  direction  like  the 
house  in  cut  77.  And  how  intense  was  the  longing  of  astronomers 
to  prove  the  Copernican  truths.  They  had  no  telescopes,  and  of 
course  could  not  detect  any  shifting  among  the  stars. 

Then  came  Galileo  in  1609  with  his  miniature  telescope.  In 
time  this  was  much  improved  and  astronomers  said,  surely  now 
we  can  detect  lateral  displacement  in  the  stellar  hosts.  And  so 
they  toiled  on  year  after  year,  with  absolutely  no  result.  Even 
the  telescope  that  magnified  1500  diameters  failed  utterly  to  show 


RADIANT     ENERGY.  i95 

that  the  lines  were  not  absolutely  parallel.  And  enemies  increased. 
Astronomers  themselves  were  dumb,  and  one  of  their  number,  as 
brilliant  as  any,  Tycho,  in  despair,  gave  up  the  Copernican  theory, 
which  his  mathematical  brain  could  not  accept  on  account  of  the 
to  him  totally  impossible  magnitude  of  the  universe.  Soon  after, 
quite  a  number  of  able  astronomers  appeared,  but  none  could 
detect  any  angle  or  want  of  parallelism  between  lines  drawn  to  a 
star  from  opposites  sides  of  the  earth's  seemingly  mighty  orbit. 

BAFFLED. 

During  the  career  of  man  on  the  earth  no  such  complete 
barrier  to  his  intellectual  advance  had  been  encountered.  His 
restless  mind  was  confronted  with  a  problem — to  tell  the  distance 
of  a  star — before  which  he  now  found  himself  as  a  child  on  the 
shores  of  an  unknown  sea.  And  man  felt  himself  humiliated 
and  disconcerted.  For  perhaps  one  reason  why  Tycho  Brahe 
opposed  the  true  theory  of  Copernicus  was  the  unutterable  con- 
sequences sure  to  follow  if  it  really  were  true,  and  this  outweighed 
his  judgment.  For  let  one  cubic  inch  contain  one  million  parti- 
cles of  dust — then  in  an  ordinary  room  each  particle  is  as  large 
or  larger  in  proportion  to  the  cubical  space  in  the  room — than 
the  earth  is  to  space  shown  in  modern  telescopes. 

Thus  from  1530  to  1650,  or  120  years,  the  astronomers  of 
the  world  were  simply  overwhelmed  with  the  awful  majesty  of  the 
sidereal  structure.  The  more  they  studied  the  more  the  mighty 
concept  grew  and  the  more  absolutely  insignificant  did  the 
earth  and  man  become.  And  the  problem  of  measuring  the  dis- 
tance of  a  star  seemed  past  human  solution. 

THE    MICROMETER. 

About  1650  this  marvelous  engine  for  the  conquest  of  the 
universe  was  invented.  Hope  revived,  all  was  animation 
in  the  astronomical  world,  incredible  labors  rivaling  the  works 
of  Hercules  were  commenced,  observatories  were  erected,  men 


ig6  RADIANT     ENERGY. 

toiled  as  only  men  will  if  they  are  on  a  sinking  ship.  Mathe- 
matics expanded,  the  lethargy  of  the  dark  ages  was  aroused  into 
a  scene  of  activity,  which  even  now  is  increasing  in  momentum 
in  geometrical  progression. 

Of  such  extreme  value  is  the  micrometer,  and  so  far  reaching, 
epoch  making  and  important  in  the  evolution  of  intelligence,  that 
all  should  study  the  wondrous  instrument.  Cut  78  is  the  filar 
micrometer  in  the  Lowe  Observatory. 


Cut  78.    Filar  Micrometer  in  the  Ivowe  Observatory. 

Figure  17,  cut  78,  is  the  tube  which  has  a  screw  thread  at  the 
bottom,  to  adjust  to  the  telescope.  Just  below  the  eye-piece,  21, 
are  two  spider  webs  crossing,  and  when  pointing  to  the  zenith,  th^ 
eye-piece,  21,  would  be  toward  the  floor. 

A  circle  at  the  top  of  the  tube  (17) — the  edge  is  seen  with 
cogs — is  ruled  into  360  degrees  and  fractions  of  degrees,  on  its 
surface,  and  is  fixed  to  the  tube,  and  also  to  the  telescope.  The 
whole  top  from  22  to  23  turns  completely  around  by  turning  the 
screw  left  of  20.  Just  below  21  are  two  spider  webs  crossing 
the  field  of  view  of  the  lens,  carefully  protected  in  a  brass  cell. 
One  is  fixed  and  the  other  movable,  while  both  turn  when  the 
whole  top  turns.  The  webs  are  invisible  when  looking  at  the 
night  sky.  So  they  must  be  illuminated  by  the  lamp  (19),  which 
shines  on  a  mirror,  not  seen  in  cut — it  is  just  behind  the  lamp — 
and  this  reflects  the  light  to  the  webs  under  21,  and  they  look 


RADIANT     ENERGY. 


197 


like  silver.  Figure  22  is  a  weight  to  balance  the  lamp.  There 
are  two  ruled  screw  heads  to  the  right  of  20.  One  shows  a 
whole  turn,  and  the  other  fractions  of  a  turn  of  the  screw  that 
moves  the  webs.  The  astronomer  must  find  by  trial  on  the  stars 
the  value  of  one-hundredth  turn,  and  so  on.  It  is  an  instru- 
ment of  great  power,  and  has  enabled  man  to  unlock  doors  of 
hitherto  inscrutable  labyrinths  in  space. 

The  micrometer  (cut  78)  is  Clark's,  and  is  so  much  superior 
to   early   forms   that   comparison   is   useless. 


Cut  78A.     Heliostat,  Adjusting  Mirror  and  Spectroscope  in  I^owe  Observatory. 


If  the  eye  is  placed  at  21,  a  scene  of  beauty  (cut  79)  is  on 
display,  which  is  a  field  of  view  where  a  double  star  is  being 
measured.  The  webs  are  represented  as  turned  in  two  directions. 

The  webs,  wide  apart,  are  shown  bisecting  the  large  star  and 
its  smaller  companion,  and  their  distance  apart  is  read  on  the 
edges  of  the  external  circle.  The  webs — close  together — measure 
the  angular  position  of  a  line  joining  the  two  stars  with  the 
meridian  N.  S.  in  cut,  for  the  place  of  the  celestial  equator  is 


RADIANT     ENERGY. 


always  known  from  the  diurnal  motion  of  the  stars  across  the  field, 
and  is  shown  E.  W. 

Now  watch  these  stars  for  say  from  ten  to  twenty-five  years, 
making  careful  measures  of  their  angle  with  the  meridian,  and 
their  distance  apart  each  time,  perhaps  once  a  year.  If  the  dis- 
tance and  angle  is  the  same  at  every  observation,  it  is  concluded 
that  the  star  is  not  a  binary ;  that  is,  they  do  not  revolve  around 
their  common  center  of  gravity.  If  they  do  not,  then  they  are  a 
first-class  pair  for  use  in  a  trial  to  see  if  they  suffer  any  displace- 
ment, looked  upon  from  opposite  sides  of  the  earth's  orbit,  at 
intervals  of  half  a  year. 

In  1669,  Hooke  tried  the  star  Gamma  Draconis  for  six  months 
and  found  a  parallax  of  29  seconds !  This  would  make  its  dis- 


Cut  79.    Field  of  a  Position  Micrometer. 

tance  only  7,000  times  that  of  the  sun.  Parallax  means  how  great 
an  angle  would  be  made  by  the  distance  of  the  earth  from  the 
sun,  to  a  person  standing  on  the  star  and  looking  this  way,  with 
a  micrometer  to  measure  it.  Picard  measured  the  giant  star 
Alpha  Lyrse,  and  could  not  find  any  parallax.  That  is,  the  distance 
from  the  earth  to  the  sun  would  appear  as  nothing  if  seen  from 
that  star.  Then  Flamstead,  with  untiring  zeal,  measured  the 
polar  star  from  1689  to  1697,  and  concluded  that  its  parallax  was 


RADIANT     ENERGY.  i99 

40  seconds,  from  which  its  distance  would  be  small,  5,100  times 
that  of  the  sun.  Then  came  Cassini,  who  proved  that  all  the  dis- 
placements of  stars  deduced  by  Hooke  and  Flamstead,  after 
years  of  severe  labor,  were  not  due  to  the  motion  of  the  earth. 
The  shifting  of  our  particle  of  dust,  the  earth,  had  absolutely  no 
effect  on  the  stars,  although  it  shifts  186,000,000  miles.  This  b^ow 
was  crushing,  hope  sank  out  of  the  hearts  of  astronomers,  for  how 
tell  the  distances  of  the  stars?  An  impenetrable  wall  stood 
squarely  across  the  path  of  man's  advance,  and  a  period  of  gloom 
set  in. 


200  RADIANT     ENERGY. 


XXX. 

RENEWED  EFFORTS  TO  FIND  STELLAR  PARALLAX. 

"There  is  one  universal  soul  diffused  through  all  things." — Pythag- 
oras, Greece. 

Tune  your  ear 

To  all  the  wordless  music  of  the  stars 
-.       And  to  the  voice  of  Nature,  and  your  heart 
j,     Shall   turn   to   truth  and   goodness,   as   the  plant 

Turns  to  the  sun. 
— Ella  Wheeler  Wilcox  in  her  wondrous  poem  "Progress." 

After  Cassini  upset  the  observations  of  Hooke  and  Flam- 
stead,  about  the  year  1698,  the  problem  of  measuring  stellar 
distances  was  seen  to  be  the  greatest  that  ever  confronted  the 
indomitable  spirit  of  man.  But  none  came  able  to  grapple  with 
the  great  undertaking  from  1689  until  1725.  Men  shrank  and 
faltered  thirty-six  years. 

Then  came  Molyneux,  an  amateur.  He  had  made  an  instru- 
ment, a  zenith  sector,  for  observing  near  the  zenith  only,  of  great 
accuracy,  the  finest  yet  constructed,  and  on  December  3,  1725, 
made  his  first  observation  on  the  star  Gamma  Draconis,  which 
culminated  almost  exactly  in  his  zenith,  and  has  this  advantage: 
it  is  only  fifteen  degrees  from  the  pole  of  the  earth's  orbit,  so. 
if  the  annual  circuit  of  the  earth  around  the  sun  made  any  appar- 
ent displacement  among  the  stars,  it  would  be  at  a  maximum 
nearly  in  this  star. 


RADIANT     ENERGY.  201 

Molyneux  observed  until  December  I7th,  when  an  event  that 
changed  ancient  astronomy  to  modern  occurred.  That  eminent 
astronomer,  Bradley,  happened  to  visit  Molyneux  in  his  labora- 
tory at  Kew,  England.  He,  out  of  curiosity,  according  to  his  own 
account,  observed  the  star.  He  found  that  it  was  farther  south 
than  as  observed  by  Molyneux  on  the  3d.  This  was  not  expected ; 
it  was  thought  that  an  error  had  been  made  in  measuring.  So 
on  the  2Oth,  both  astronomers  made  the  most  accurate  observa- 
tions possible  with  the  instrument,  and  both  found  that  the  star 
was  still  farther  south.  Intense  surprise  rilled  their  minds,  for 
the  star  was  moving  in  the  wrong  direction  to  be  caused  by  the 
motion  of  the  earth.  That  is,  if  the  earth's  movement  had  any 
effect,  it  was  obliterated  by  this  other  mysterious  shifting  of  the 
star.  Both  astronomers  now  watched  the  star  with  the  most 
absorbing  interest  every  clear  night.  Its  stately  march  ever  to 
the  south  kept  up  until  April  3<Dth,  when  it  stopped  and  remained 
motionless  until  the  middle  of  May ;  then  started  north  and  passed 
the  meridian  at  the  same  distance  from  the  zenith  as  on  the 
previous  December.  It  went  north  until  September,  when  it 
came  to  a  rest,  remained  stationary  a  few  days,  and  then  went  to 
the  extreme  south  again,  describing  a  small  ellipse  whose  longest 
diameter  was  40  seconds  of  arc. 

Theories  were  put  forth  to  account  for  this  new  wonder,  and 
none  were  satisfactory.  Bradley  set  himself  to  the  mighty  problem 
to  find  the  cause,  and,  like  Columbus,  put  out  into  an  unknown 
and  to  him  shoreless  sea.  He  had  a  zenith  sector  constructed 
with  all  the  precision  of  the  most  skillful  mechanics  of  England. 
He  had  it  made  with  a  wide  angle,  so  he  could  get  the  first  mag- 
nitude star  Capella  within  its  range,  for  Gamma  Draconis  is  of  less 
than  the  second  magnitude. 

It  was  hopeless  to  try  to  find  the  displacement — parallax  of 
any  star — due  to  the  motion  of  the  earth  until  this  new  motion  in 
the  wrong  direction  should  be  completely  explained. 


202  RADIANT     ENERGY. 

An  eventful  and  auspicious  day  came  to  Wansted,  England, 
August  19,  1727,  the  new  sector  was  placed  in  position,  and 
Bradley  began  that  memorable  and  now  historic  and  classic  series 
of  observations,  only  surpassed  in  accuracy  by  the  most 
modern  and  perfect  instruments.  Every  favorable  hour  of  every 
clear  night  throughout  his  first  year  was  improved ;  precious  time 
was  not  wasted,  and  Bradley  soon  found  that  wobbling  of  the 
axis  of  the  earth  was  not  the  cause — for  it  does  wobble  like  the 
axis  of  a  spinning  top.  This  alone  was  a  great  achievement. 
He  next  proved  that  changes  of  density,  and  therefore  in  refrac- 
tion of  the  earth's  atmosphere  at  different  seasons  of  the  year, 
were  not  able  to  cause  the  deceptive  and  illusory  motion  in  the 
stars.  This  was  another  great  work.  He  then  tried  to  find  if  a 
plumb  line  shifted  on  the  earth  so  as  to  make  the  zenith  appear 
to  make  lateral  movement.  This  he  proved  untenable.  The  his- 
torian says  Bradley  "pondered." — Grant's  Hist,  of  Astronomy. 

But  in  1675  Roemer  noticed  that  when  the  earth  and  Jupiter 
were  on  opposite  sides  of  the  sun,  eclipses  of  the  moons  of  Jupiter 
occurred  16  minutes  and  38  seconds  later  than  they  did  when  the 
earth  and  Jupiter  were  on  the  same  side  of  the  sun — the  earth 
between.  He  knew  that  nature's  laws  are  invariable,  and  that  the 
time  of  the  eclipses  did  not  vary.  So  he  inferred  that  it  took 
light  16  minutes  and  38  seconds  to  traverse  the  diameter  of  the 
earth's  orbit,  or  186,000,000  miles. 

None  of  the  astronomers  had  power  to  grasp  this  stupendous 
concept.  Such  incredible  velocities  were  too  terrific,  the  minds 
of  able  men  were  again  overwhelmed,  and  once  more,  even  mathe- 
maticians quailed  and  their  hearts  subsided  and  shrank  in  the 
majestic  and  awful  presence  of  nature.  So  appalling  was  this 
concept  of  Roemer  that  none  accepted  it  for  more  than  fifty  years, 
and  he  died  before  anybody  believed,  or  even  could  believe.  Pro- 
fessor Young  says  Roemer  was  100  years  before  his  time  on  earth. 

But  Bradley,. in  1728,  after  one  year  of  observation,  believed. 


RADIANT     ENERGY.  203 

His  brain  saw,  that  since  light  moves  186,000  miles  per  second,  and 
the  earth  18^2  miles  in  the  same  time,  that  the  combined  effect  of 
the  two  motions  would  make  the  star  traverse  a  minute  orbit 
exactly  of  the  same  shape  as  the  earth's  track  around  the  sun. 
With  feverish  anxiety  he  proceeded  to  solve  the  angles  resulting 
from  the  combinations  of  these  motions  to  see  if  the  major  axis 
of  the  star's  ellipse  would  come  out  40  seconds  in  length.  One 
can  scarcely  imagine  with  what  intense  nervous  energy  the  pencil 
of  Bradley  flew  over  the  paper.  The  formulas  of  trigonometry 
were  instantly  called  into  use,  equations  solved,  and  excitement 
grew  as  the  problem  approached  solution,  with  a  stupendous  truth 
for  its  ending. 

With  a  diameter  of  the  earth's  orbit  186,000,000  miles,  the 
speed  of  light  186,000  miles  per  second,  and  the  velocity  of  the 
earth  18^2  miles,  the  transverse  axis  of  the  ellipse  cut  out  by  a  star 
at  the  pole  of  the  orbit  of  the  earth  is  now  known  to  be  41  seconds 
of  arc.  That  is,  Bradley  with  his  sector,  almost  reached  the  pre- 
cision of  modern  astronomy. 

Every  astronomer  on  earth  at  once  adopted  Roemer's  truth — 
the  speed  of  light.  The  recondite  physical  fact  discovered  by 
Bradley  has  from  that  moment  been  considered  one  of  the  greatest 
achievements  of  the  human  mind,  and  is  called  aberration  of  light. 
He  proved  the  velocity  of  radiance  independently  of  Jupiter's 
satellites. 

This  vast  subject  ought  to  be  understood;  and  here  is  the 
most  elementary  explanation.  In  cut  80,  I,  2,  3  represent  tubes, 
and  4  and  5  falling  bodies. 

If  tube  i  remains  at  rest,  the  ball  (4)  will  strike  the  bottom, 
but  in  order  that  5  may  reach  the  base,  the  tube  must  be  inclined 
to  allow  ball  5  to  enter  as  shown,  and  move  in  the  direction  of  the 
arrow  in  position  3,  in  the  same  time  it  takes  ball  5  to  fall.  If 
the  times  are  equal,  it  is  evident  that  the  falling  body  will  be  at 
the  bottom  of  tube  3. 


RADIANT     ENERGY. 


Cut  80.    Aberration  of  Light. 


Call  4-5  waves  of  light,  moving  186,000  miles  per  second, 
and  the  distance  of  the  bottom  of  tube  3  from  i,  iSy2  miles,  and 
the  direction  of  motion  an  arc  of  the  earth's  orbit,  while  the 
tubes  are  telescopes,  then  it  follows  that  the  telescope  must  be 
inclined  throughout  the  year.  The  star  will  always  be  displaced 
in  advance,  equal  to  the  inclination  of  the  telescope. 


Cut  81.    Sun,  Karth's  Orbit  and  Aberration  of  L,ight. 

Cleared  in  cut  81,  showing  the  sun  and  the  earth's  path 
around  it,  the  earth  moving  in  direction  of  the  arrows.  Let  figure 
I  be  the  earth's  place  at  the  beginning,  and  2  at  the  end  of  one 
second  of  time,  with  telescopes  receiving  rays  of  light  from  a 
star.  The  distance  between  i  and  2  is  iSj/2  miles.  The  telescope 
(O)  is  receiving  light  from  the  star  along  its  axis  at  the  bottom 
— or  eye-piece — and  for  telescope  in  positions  2  and  3,  the  eye- 


RADIANT     ENERGY.  205 

end  must  be  drawn  back  as  shown,  which  makes  the  object-glass 
move  forward,  so  that  light  falling  on  it  shall  also  fall  on  the 
eye-piece.  Therefore  the  star  appears  to  be  driven  forward  in 
direction  of  dotted  lines,  where,  it  is  plain,  that  if  the  motion  of 
the  earth  had  any  effect  on  the  star,  it,  the  star,  would  be  left 
behind  and  appear  to  move  the  other  way,  and  be  seen  in  direction 
of  the  line  O,  3. 


Cut  82.     Aberration  and  Parallax. 

Simplified  in  cut  82,  where  both  phenomena  are  shown. 

Figure  I  shows  the  effect  of  aberration,  and  2,  paralL'-.x,  for 
the  arrows  at  I  and  2  are  in  opposite  directions.  The  ellipses  at 
i  and  2  are  those  minute  orbits  apparently  traversed  by  the  star 
in  a  year. 

The  reader  must  not  be  in  error  here,  for  the  lines  from  oppo- 
site sides  of  the  sun,  186,000,000  miles,  to  the  star  are  drawn  par- 
allel. They  should  come  to  a  very  near  approach,  41  seconds  of 
arc,  in  the  aberrational  ellipse,  and  to  an  exceedingly  fine  point 
at  the  parallactic  ellipse,  since  the  whole  earth's  orbit  as  seen  from 
the  nearest  star  amounts  to  almost  nothing,  totally  invisible  with- 
out a  telescope,  placed  on  the  star  and  looking  this  way.  The 
ellipse  of  aberration  even  cannot  be  noticed  without  a  powerful 
telescope  and  micrometer,  also,  it  is  so  very  small. 

Bradley  started  to  find  the  parallax  of  a  star  and  found  one 
of  the  chief  wonders  of  all  ages — the  aberration  of  radiance.  But 


206  RADIANT     ENERGY. 

the  stars !  the  stars !  It  seemed  that  it  was  beyond  the  power  of 
man  to  tell  their  mighty  distances,  for  Bradley,  the  best  astronomer 
so  far  had  failed.  And  he  said  he  felt  sure  that  if  it  had  a  value  of 
one  second  he  would  have  detected  it.  It  is  known  now  he  could 
not  with  his  sector.  Discomfiture  and  depression  fell  upon  the 
minds  of  the  astronomers  of  Europe.  Several  tried  it,  and  all 
failed.  Matters  went  on  from  1727  to  1790  with  no  results,  when 
Sir  William  Herschel  began  by  observing  double  stars.  He 
labored  long,  and  instead  of  finding  parallax  made  a  most  import- 
ant discovery — binaries — that  is,  where  two  suns  revolve  about  a 
common  center. 

At  the  opening  of  the  nineteenth  century  came  Piazzi,  who 
tried  to  measure  the  distances  of  the  great  suns  Sirius  and  Pro- 
cyon.  He  made  out  that  the  distance  of  Sirius  was  one-tenth  of 
what  it  actually  is.  Then  came  the  Russian  astronomer  Struve 
and  found  displacements  of  stars  insensible — so  far  away  that 
the  motion  of  the  earth  had  no  effect.  This  was  from  1818  to 
1821.  In  1835  he  watched  Vega  for  six  months  and  made  its 
distance  one-half  of  its  real  value.  All  these  troubles  came  from 
poor  micrometers,  bad  object-glasses  and  from  the  fact  that  refrac- 
tion in  the  earth's  atmosphere  had  not  been  determined  with  rigid 
accuracy.  Due  allowance  had  not  been  made  for  pressure,  tem- 
perature and  water  vapor.  Now  the  barometer,  thermometer  and 
hygrometer  are  carefully  noted.  Other  complex  motions  of  the 
'earth  too  abstruse  to  be  explained  in  elementary  notes  had  not 
been  found  with  precision,  so  failure  was  inevitable. 

BESSES. 

Then  the  mighty  brain  of  Bessel  came  to  the  rescue  in 
Konigsberg.  He  had  made  an  instrument  on  a  new  principle  (its 
technical  description  must  be  omitted),  the  heliometer,  of  sur- 
prising accuracy.  He  did  not  measure  the  exact  position  of  the 


RADIANT     ENERGY.  207 

stars  when  they  passed  the  meridian,  like  Bradley  and  his  suc- 
cessors. 

Bessel  used  the  method  of  differences.  This  must  be  under- 
stood by  all  who  wish  to  see  the  solution  of  the  most  remarkable 
work  and  arduous  ever  performed  by  man. 


Cut  83.     Bessel's  Method. 

Cleared  in  cut  83,  where  the  sun  and  orbit  of  the  earth  are 
shown  as  before.  Let  figure  I  be  the  star  whose  distance  from 
the  sun  is  sought.  Five  stars  are  shown  near  it,  and  an  enlarged 
view  of  them  at  A.  The  plan  is  that  of  triangulation,  the  same  as 
that  employed  on  the  earth's  surface  by  surveyors.  The  five  stars 
are  at  such  tremendous  distances'  that  the  186,000,000  miles, 
the  diameter  of  the  earth's  orbit  (2,  3)  is  nothing  as  seen  from 
them.  Hence  these  stars  appear  stationary.  All  triangles  at  A  are 
measured  during  the  year,  while  the  earth  moves  from  2  around 
3,  and  to  2  again,  with  the  greatest  accuracy  and  results  recorded. 
At  the  end  of  the  year  all  the  angles  are  solved,  and  if  the  angles 
from  each  of  the  five  stars,  to  all  the  others  of  the  five,  are  equal 
to  their  values  in  the  beginning  of  the  year,  proof  is  had  that  they 
'have  not  moved,  but  if  all  the  angles  made  by  each  of  the  five 
stars  with  star  I  are  unequal,  star  I  has  apparently  moved. 
Solving  all  these  triangles,  a  stupendous  result  is  obtained — the 


208 


RADIANT     ENERGY. 


angle  4,  I,  5  is  found!  But  by  elementary  geometry  it  is  known 
to  be  equal  to  the  opposite  angle,  2,  i,  3.  The  distance  from  2 
to  the  sun  being  known,  it  is  merely  a  question  of  simple  division 
to  find  the  side  (S,  i),  the  distance  of  the  star.  The  radius  of 
the  earth's  orbit  (S,  2,  or  S,  3),  is  called  the  parallax  of  the 
star  i,  and  S,  i,  2  is  its  angular  value  as  seen  from  the  star — 
usually  the  thickness  of  a  spider's  web,  but  really  93,000,000  miles. 
The  labors  of  Bessel  surpassing  those  of  Hercu!es  continued 
from  1837  to  1840,  on  the  star  61  Cygni.  Bessel  used  two  small 
but  vastly  more  distant  comparison  stars,  but  later  observers  have 
used  more,  and  other  stars. 


The  Eclipsed  Sun. 


RADIANT     ENERGY.  209 

HENDERSON. 

While  Bessel  in  Konigsberg  was  reducing  his  observations, 
Henderson  in  London  was  deriving  final  deductions  from  re- 
searches made  by  him  on  Alpha  Centauri  in  1832-3  at  the  Cape 
of  Good  Hope,  South  Africa,  which  star  is  the  nearest  neighbor 
the  sun  has,  so  far  as  at  present  known.  Thus  Hooke  began  the 
great  work  of  finding  the  distance  of  a  star  in  1669  and  one  was 
found  in  1839,  a  continuous  struggle  during  170  years.  This 
labor  surpasses  all  other  work  of  human  hands.  The  Pyramid  of 
Suphis  cannot  compare  with  it,  for  astronomers  toil  as  none  others 
among  men  toil,  with  brain,  nerve  and  gross  body.  Here  is  the 
all-important  number — that  valued  number  that  cost  more  than 
any  other,  representing  now  more  than  two  centuries  of  skilled 
labor ;  that  magic  number,  that  sounding  line  sunk  in  space,  that 
unit  of  stellar  measures,  that  precious  key  whose  power  is  to 
unlock  the  labyrinth  of  the  sidereal  universe;  that  number  whose 
value  cannot  be  compared  to  anything  in  the  possession  of  man 
is  now  known  to  be,  from  the  latest  determinations. 

.  75   SECOND  OF  ARC. 

That  is,  go  to  Alpha  Centauri,  with  a  telescope  of  high  power 
and  perfect  micrometer,  and  look  this  way.  Then  the  distance 
from  the  earth  to  the  sun  will  shrink  to  only  three-fourths  of  a 
second ! 

The  word  second  must  be  explained.  Take  a  child's  marble, 
a  ball  one  inch  in  diameter,  to  a  distance  of  three  and  one-fourth 
miles,  and  its  angle  at  the  eye  will  be  one  second.  A  powerful 
telescope  would  be  required,  and  a  still  more  powerful  micrometer 
to  measure  it.  Since  the  parallax  is  only  three- fourths  second,  the 
marble  must  be  moved  four  and  one-third  miles  away  to  appear  to 
be  that  of  angular  diameter.  It  is  no  wonder  that  200  years  were 
consumed. 

Bessel  and  Henderson  both  made  their  parallaxes  too  large, 


210  RADIANT     ENERGY. 

and  the  stars  too  near,  for  the  greater  the  parallax  the  less  the 
star's  distance,  so  it  is  only  lately  that  the  value,  .75  second,  was 
obtained  by  the  most  perfect  instruments  ever  made.  But  now 
comes  the  standing"  marvel  of  the  centuries — photography — for  all 
the  stars  near  the  one  being  measured,  as  in  Bessel's  problem, 
are  photographed,  and  the  negative  measured  with  a  microscope 
at  leisure.  Since  the  parallax  is  only  three-fourths  second,  the 
marble  must  be  moved  four  and  one-third  miles  away  to  appear  to 
be  of  that  angular  diameter. 

HOW   TO  TEU,  THE  DISTANCE  OF  A   STAR. 

This  can  be  done  by  using  a  radian,  without  resort  to  sines, 
cosines,  tangents,  etc. 


Cut  84.     A  Radian. 

Cut  84  shows  a  radian,  the  angle  2,  1,3. 

A  radian  is  the  angle  measured  by  an  arc,  equal  in  length 
to  the  radius  of  any  circle.  In  cut  84  the  line  1-2  is  the  radius, 
then  if  the  arc  of  the  circle  from  2  to  3  is  57^/3  degrees 
its  length  is  the  same  as  the  radius.  Hence  if  a  person  stands 
at  figure  I  and  sees  a  sphere  or  straight  line  that  fills  one-fifty- 
seventh  of  the  curve  2-3,  its  angular  diameter  is  one  degree,  and 
no  matter  what  the  real  diameter  of  the  object  is,  he  knows  that 
it  is  57  1-3  times  that  diameter  in  distance.  In  a  circle  there  are 
1,296,000  seconds,  and  in  57^/3  degrees  there  are  206,265  seconds; 
and  if  the  observer  measures  any  object  with  micrometer  whose 
angular  diameter  comes  out  one  second,  he  knows  that  its  distance 
is  206,265  times  its  actual  diameter  in  miles,  or  inches. 


RADIANT     ENERGY.  211 

In  two  hundred  years  men  found  that  the  angular  value  of 
the  distance  of  the  earth  from  the  sun  as  measured  by  a  microm- 
eter placed  on  the  nearest  star  is  .75  or,  three-fourths  of  one 
second;  so  206,265  divided  by  three-fourths  equal  275,202,  the 
number  of  times  the  star  is  more  distant  than  the  sun. 


212  RADIANT     ENERGY. 


XXXI. 
THE    SIDEREAL    STRUCTURE. 


'Twas  the  morning  of  time 

When  yet  naught  was ; 

Nor  sand  nor  sea  were  there, 

Nor  cooling  streams ; 

Earth  was  not  formed, 

Nor  heaven  above; 

A  yawning  gap  there  was. 

-Grand  "Hymn  of  Creation,"  the  Edda,  Scandinavian  Scriptures. 

As  yet  the  world  was  not, 

And  Chaos  wild 

Reigned  where  the  heavens  now  roll 

And  where  the  earth  now  rests.  — Milton. 


INTERMINABLE  SPACE. 

In  cut  85  let  S  represent  the  sun,  and  E  the  earth,  distant 
three  inches ;  then  the  distance  to  the  nearest  star  is  thirteen  miles. 
This  distance  is  so  stupendous  that  the  mere  attempt  to  think 
about  it  is  crushing  to  the  mind.  .Here  are  times  to  traverse 
the  mighty  void : 

Train  of  cars,  one  mile  per  minute,  47,528,000  years ;  the  earth 
on  its  orbit,  18^  miles  per  second,  42,823  years ;  light,  186,000 
miles  per  second,  4.26  years.  And  upon  arriving  at  the  star  the 
traveler  has  not  more  than  made  a  start  from  home,  has  scarcely 


RADIANT     ENERGY.  213 

passed  from  his  front  gate,  for  the  heavens  as  seen  from  there 
would  appear  sensibly  the  same  as  from  here,  he  would  not  know 
he  had  moved,  and  could  not  tell  which  star  was  his  own  sun, 
for  they  all  would  look  as  much  alike  as  they  do  now,  our  sun 
being  merely  a  small  star,  similar  to  all  the  others. 


TO 

s 

Q     I  '3  MILES. 

Cut  85.    Distance  From  Sun"  to  Star. 

Nature  is  incredibly  lavish  with  her  space,  and  astronomers 
are  unable  to  see  why  it  is  necessary  for  all  suns  to  be  separated 
by  such  unfathomable  distances.  For  if  our  sun  and  Alpha  Cen- 
tauri  were  to  approach  to  one-eighth  their  present  distance  apart, 
it  is  doubtful  if  the  planets  revolving  around  each  would  be  per- 
turbed by  any  amount  capable  of  being  detected  by  a  micrometer. 
A  number  of  microscopes  have  been  made  that  show  particles 
requiring  100,000  side  by  side  to  occupy  one  inch.  Each  one  of 
these  is  larger,  proportionately,  to  one  cubic  inch  than  the  earth 
is  to  space  revealed  by  modern  telescopes. 

If  the  universe  whether  finite  or  infinite  is  peopled  with  intel- 
ligent beings,  they  have  not  heard  of  the  earth  nor  the  human 
race.  We  are  unknown,  and  if  the  earth  and  every  inhabitant 
be  instantly  annihilated,  the  little  event  would  be  entirely  unknown 
to  space,  and  not  the  slightest  difference  would  be  made,  except 
minute  disturbances  in  our  own  local  solar  system.  And  should 
the  sun  and  all  the  planets  be  destroyed  in  one  second,  no  differ- 
ence whatever  could  be  detected  in  the  sidereal  edifice.  Only  a 
professional  astronomer  on  some  planet  near  an  adjacent  sun 
would  miss  it,  and  not  he,  unless  he  had  an  accurate  star  catalogue 
and  made  close  examination  among  its  millions. 


214.  RADIANT     ENERGY. 

NUMBER   OF  THE   LUCID  STARS. 

By  lucid  stars  is  meant  those  visible  to  a  good  eye  on  a  dark 
clear  night  without  optical  aid.  By  actual  count  the  number  is 
6,874,  from  the  brightest  to  the  sixth  magnitude — the  extreme 
limit,  for  the  seventh  magnitude  cannot  be  seen  without  a  tele- 
scope. Half,  or  3,437,  are  above  the  horizon  at  the  same  time. 
But  fourth,  fifth  and  sixth  magnitudes  cannot  be  seen  when 
within  fifteen  degrees  of  the  horizon,  owing  to  the  increased 
depth  of  air,  water  vapor  and  dust,  even  on  a  "clear"  night.  So 
the  maximum  visible  at  the  same  time  is  about  2,000.  But  an 
opera  glass  brings  the  seventh  magnitude  into  view  and  vastly 
increases  the  number. 

Magnitudes  are  not  based  on  size,  for  all  the  stars  are  points 
without  diameter  even  in  the  largest  telescopes,  but  on  their 
apparent  brightness.  The  leaves  of  the  trees  in  a  forest  vary  by 
insensible  gradation  from  bud  to  the  "sere  and  yellow  leaf,"  and 
stars  vary  from  the  faintest  in  the  Yerkes  telescope  to  the  bright- 
est of  all,  Sirius.  Still,  astronomers  have  classified  all  by  magni- 
tudes on  the  following  photometric  scale:  An  average  star  of 
the  first  magnitude  is  2^/2  times  more  brilliant  than  one  of  the 
second,  and  one  of  the  second  is  2^  times  brighter  than  one 
of  the  third,  and  so  on  in  geometrical  progression,  the  constant 
multiplier  being  2^,  and  by  continuing  to  the  sixth  magnitude  it 
comes  out  that  it  takes  100  stars  of  that  magnitude  to  give  as  much 
light  as  one  of  the  first  magnitude. 

All  the  stars  visible  from  Harvard  College  Observatory  have 
had  their  light  measured  by  a  meridian  photometer,  devised  by 
Professor  E.  C.  Pickering.  The  light  sent  hither  by  Polaris,  the 
North  star,  is  used  as  the  standard  of  comparison.  The  telescope 
is  set  east  and  west,  and  has  two  object-glasses.  In  front  of  each 
is  a  mirror  inclined  at  an  angle  of  45  degrees.  It  is  clear  that 
these  mirrors  must  be  in  the  meridian,  if  the  telescope  makes  a 


ENERGY. 

right  angle  with  it.  One  mirror  reflects  the  light  from  the  polar 
star  into  the  telescope,  while  the  other  reflects  the  light  from  any 
other  star  that  may  be  crossing  the  meridian,  the  two  lights  falling 
side  by  side  for  comparison  by  a  Nicol.  The  standard  first  magni- 
tude star  is  Aldebaran,  the  bright  star  in  Taurus,  the  first  in  the 
Y  shaped  cluster,  the  Hyades. 

Bright  as  it  is,  its  distance  is  1,778,000  times  greater  than 
that  of  the  sun,  or  1,778,000  multiplied  93,000,000  miles. 

What  an  inconceivably  hot  and  large  sun  it  is !  Should  the 
earth  come  anywhere  in  its  vicinity  it  would  be  turned  to  gas  so 
rare  that  it  would  be  invisible.  And  the  stars  Sirius  and  Canopus 
are  very  much  brighter  and  hotter  than  Aldebaran.  The  distance 
of  Canopus  just  visible  over  the  waves  of  the  sea  south  of  here, 
but  invisible  from  San  Francisco,  is  so  enormous  that  the  swing 
of  that  pendulum  the  earth,  of  186,000,000  miles,  is  absolutely 
insensible  as  seen  from  that  giant  sun ;  that  is,  the  parallax  of 
Canopus  is  oo !  What  brain  can  imagine  its  terrific  heat  or 
dimensions? 

Since  Sirius  and  Canopus  are  brighter  than  Aldebaran — the 
star  that  it  has  been  agreed  to  call  first  magnitude — they  must 
have  negative  magnitudes.  Thus  Arcturus  sends  us  twice  as 
much  light  as  Aldebaran,  so  its  magnitude  is  oo,  and  Sirius — 1.4. 

Thus  it  would  take  10,000  stars  of  the  eleventh  magnitude 
and  1,000,000  of  the  sixteenth  to  emit  the  same  quantity  of  light 
poured  forth  by  the  mighty  Aldebaran.  The  36-inch  telescope  of 
the  Lick  Observatory  brings  into  view,  stars  between  the  sixteenth 
and  seventeenth  magnitude,  and  the  4O-inch  Yerkes  reveals  to 
human  vision  down  to  the  seventeenth,  while  the  i6-inch  in  this 
observatory  brings  forth  from  space  the  fifteenth.  But  the  air 
is  so  nearly  chemically  pure  here  that  in  all  probability  faint  stars 
to  the  magnitude  of  fifteen  and  one-half  can  be  seen,  strewn  like 
faintly  sparkling  gems  on  the  awful  blackness  of  iririnite  space. 
Since  the  ratio  of  progression  of  stellar  light  is  2.V2  a  table  can 


216  RADIANT     ENERGY. 

be  continued  from  the  visible  to  the  invisible  regions,  if  there  are 
stars  beyond  the  powers  of  the  4O-inch. 

Numbers 
Magnitudes.  of  stars. 

First    20 

Second    65 

Third    200 

Fourth    500 

Fifth    1,400 

Sixth    5,ooo 

Seventh    20,000 

Eighth    68,000 

Ninth    240,000 

Tenth    720,000 


Total     1,055,000 

These  have  been  counted  with  more  or  less  accuracy,  notably 
by  Professor  Gould.  There  are  some  irregularities,  for  65  multi- 
plied by  2*/2  equals  162  as  the  number  of  third  magnitude,  while 
there  are  200.  However,  carrying  out  the  formula  to  the  end  of 
the  seventeenth  magnitude,  their  number  would  be  440,000,000. 
The  total  in  the  table  to  the  end  of  the  tenth  is  1,055,000;  so,  by 
adding  successive  numbers  from  the  end  of  the  tenth  to  that  of 
the  seventeenth,  the  result  is  733,000,000. 

A  world's  council  of  astronomers  was  held  in  Paris  in  1887. 
An  agreement  was  made  to  photograph  the  entire  celestial  vault 
for  future  generations.  The  gigantic  work  was  assigned  to 
eighteen  observatories  in  different  parts  of  the  world,  so  all  the 
sky  could  be  included.  All  the  telescopes  were  to  be  1 3-inch,  all 
alike,  and  the  tele-cameras  were  also  alike,  the  plates  being  there- 
fore similar. 


RADIANT     ENERGY.  217 

Cut  86  shows  the  telescope  and  tele-camera  in  Paris.  Infinite 
space  studded  with  diamonds,  sapphires  and  rubies  is  seen  through 
an  opening  in  the  dome.  One  of  the  famous  Henry  brothers  is 
centering  the  telescope  on  a  region  of  the  sky  to  be  graphed, 
while  the  other  is  bringing  a  plate  to  be  inserted  in  the  plate- 
holder  of  the  camera,  as  shown  at  A.  The  inclined  frame  (B) 
holding  both  the  telescope  and  the  tele-camera,  is  placed  parallel 
to  the  axis  of  the  earth  with  great  accuracy — that  is,  it  is  pointing 
to  the  north  pole.  The  driving  clock  is  started  as  soon  as  the 
plate  is  pushed  in.  Exposure  is  then  made,  and  the  clock  turns 
the  whole  apparatus  west  as  fast  as  the  earth  rotates  to  the 
east,  so  the  stellar  images  formed  by  the  object-glass  of  the 
photographic  telescope  shall  fall  constantly  in  the  same  place. 
Exposure  has  been  made  from  one  to  eight  hours,  the  plate  storing 
the  radiance,  thus  bringing  countless  thousands  of  stars  into  view, 
invisible  in  any  telescope,  all  because  the  eye  does  not  store  energy. 
The  object-glass  of  the  telescope — made  for  seeing — is  unfit  for 
graphic  purposes,  for  the  waves  that  oscillate  with  rates  to  "shake 
down"  the  silver  salt  are  too  rapid  to  be  seen,  so  two  objectives 
are  in  the  upper  end,  one  in  the  tele-camera  and  the  other  in  the 
telescope,  each  having  a  different  focal  length. 

GRAPHIC   RESULTS. 

The  thirteen  telescopes  were  nearly  like  this  one,  and  wrought 
a  work  beside  which  pyramid,  palace  and  obelisk  is  antiquity  pale 
and  faint. 

The  total  number  of  plates  required  to  graph  the  entire  side- 
real vault  is  22,054.  Two  sets  were  to  be  taken,  one  with  ex- 
posure long  enough  to  get  images  of  all  the  twelfth  magnitude 
and  the  other  all  down  to  the  end  of  the  fourteenth.  The  stars  on 
the  first  set  were  all  to  be  measured  as  to  position  and  then  cata- 
logued. When  finished  the  plates  will  show  between  two  and 


Cut  80.    Henry  Brothers'  Telescope,  Paris, 


RADIANT     ENERGY.  219 

three  million  stars.  It  was  agreed  later  to  make  three  exposures 
of  each  plate,  so  shifted  that  each  star  shall  appear  at  the  three 
angles  of  a  minute  triangle — a  plan  which  eliminates  all  errors. 

Reports  are  in  from  many  of  the  observatories,  and  16,000 
graphs  have  been  secured.  Some  plates  show  5,000  stars.  Many 
'in  different  parts  of  the  heavens  have  been  counted,  and  a  series 
of  averages  computed.  There  are  30,000,000  suns  to  the  twelfth 
magnitude.  Part  of  the  plates  exposed  longer  for  the  fourteenth 
magnitude  have  been  treated  and  the  sum  indicated  is  50,000,000. 
Thus  photography  in  a  few  years  has  performed  a  work  that 
would  take  centuries  of  labor  by  all  the  astronomers  of  the  world 
to  complete.  Other  graphs  with  still  longer  exposure  have  been 
secured,  counts  made,  estimates  formed,  the  calculus  of  probabili- 
ties applied,  and  computations  reveal  that  the  probable  number  of 
stars  visible  on  all  the  plates  to  the  end  of  the  seventeenth  magni- 
tude is  not  less  than  100,000,000. 

Professor  Simon  Newcomb  says :  "The  photographic  maps 
now  being  made  probably  show  more  than  50,000,000,  perhaps 
100,000,000,  possibly  twice  that  number."  This  includes  all  that 
possibly  can  appear  on  the  best  plates  with  all  night  exposures, 
and  may  include  the  eighteenth  magnitude  if  there  are  any.  But 
as  shown,  by  carrying  out  the  formula  of  progression  to  the 
seventeenth  magnitude,  using  the  standard  ratio  of  2.5,  the  num- 
ber came  out  733,000,000.  From  this  it  follows  that  there  is 
actually  a  thinning  out  of  stars  from  the  thirteenth  to  the  seven- 
teenth, else  they  are  not  as  bright,  or  if  the  733,000,000  exist, 
their  light  is  quenched  in  space,  by  an  absorbing  medium,  or  by 
cosmic  dust,  or  by  the  primordial  corpuscles.  In  absence  of  any 
of  these  causes  it  is  not  known  that  radiance,  that  affects  plates 
most,  can  go  on  vibrating  763  million  million  times  per  second 
indefinitely.  In  these  notes,  the  number  of  suns  that  will  finally 
appear  when  all  the  plates  are  measured  will  be  taken  as  falling 
between  100  and  125  million. 


220 


RADIANT     ENERGY. 


m 


Cut  87.     Professor  E-  E-  Barnard's  Famous  Camera  — The  Willard  ;L,enses. 

In  cut  87  is  the  camera  with  which  Professor  E.  E.  Barnard 
took  his  remarkable  series  of  graphs  of  the  Milky  Way. 


RADIANT     ENERGY.  227 


XXXII. 

THE    STELLAR   UNIVERSE. 

"When  the  heaven  above  and  the  earth  below  were  as  yet  unnamed, 
the  abyss  and  the  billowy  sea  were  the  beginning  of  things." — Chaldean 
Hymn  of  Creation. 

If  a  meteor  half  an  inch  or  more  in  diameter  falls  toward 
the  earth,  it  rushes  with  great  velocity  through  the  air  and  friction 
liberates  intense  heat.  The  meteor  is  dissipated  into  very  fine 
dust,  which  may  take  a  month  to  reach  the  earth's  surface.  But 
at  the  instant  of  disintegration,  the  most  brilliant  flash  of  light  is 
seen.  With  small  meteors  the  light  shines  from  one  to  five  or  s'x 
seconds.  The  longer,  the  more  heat,  and  therefore  the  more  light. 
Thus  from  this  observatory  on  November  I5th,  1901,  a  large 
meteor  separated  light  that  remained  fourteen  minutes. 

The  total  light-emitting  period  of  all  suns,  bears  about  the 
same  proportion  to  their  entire  duration  that  this  fourteen-minute 
meteor's  flash  bears  to  its  duration.  Light  and  also  heat  are  but 
mere  episodes  in  the  evolution  of  matter.  In  the  twenty-seventh 
chapter  it  was  shown  that  the  sun's  light-giving  epoch  is  more 
than  22,000,000  years,  a  time  comparable — with  its  mass — to  the 
meteoric  fourteen  minutes,  and  its  mass. 

It  is  now  known  and  will  be  proven  in  a  subsequent  chapter, 
that  the  number  of  cool  dark  bodies,  like  the  earth  and  Mars,  and 
larger  still — dead  suns — is  so  inconceivably  greater  than  living- 
suns  that  they  cannot  be  compared,  even.  The  sidereal  edifice  is 


222  RADIANT     ENERGY. 

of  the  most  incredible  antiquity,  and  only  100,000,000  live  suns 
now  remain,  mere  funeral  tapers  to  illuminate  with  their  tiny 
firefly  light  the  cheerless  and  solitary  paths  of  darkened  suns  and 
frigid  worlds.  Evolution  is  stamped  indelibly  on  the  mighty 
facade  of  the  cosmical  temple.  The  process  is  continuous,  and  is 
now  in  an  active  state.  For  that  marvel  of  all  ages,  the  telespec- 
troscope,  reveals  suns  in  every  possible  phase  of  evolution,  from 
the  most  archaic  gas  to  expiring  globes. 

The  entire  history  of  a  sun  is  as  well  known  as  the  evolution 
of  flower  from  seed  to  frosts  of  death.  A  human  eye  now  rests 
on  suns  almost  every  minute  of  the  year.  Not  one  can  make 
evolution  without  being  instantly  graphed.  And  the  most  pro- 
found secrets  of  nature  are  wrested  from  her  reluctant  hands,  and 
every  action  stored  on  the  wondrous  sensitive  plate.  On  every 
clear  night  in  the  year,  perfect  graphs  are  taken  at  the  Harvard 
College  Observatory  in  Cambridge,  and  also  at  its  branch  obser- 
vatory high  on  the  mountains  in  Arequipa,  Peru,  S.  A.  Most  of 
the  observatories  of  the  world  now  graph  at  every  favorable  time. 
At  Harvard  a  building  is  filled  with  these  precious  negatives. 
They  should  be  placed  in  steel  vaults  in  air-tight  cases  and  en- 
closed in  a  rock-hewn  pyramid  or  temple  to  survive  another  gla- 
cial epoch. 

Future  astronomers  in  10,000  years  could  make  new  graphs 
and  compare,  to  see  what  phases  of  evolution  had  been  passed  in 
the  meantime.  If,  indeed,  the  negatives  would  keep  that  long. 
If  not,  new  prints  should  be  made  from  time  to  time  and  depos- 
ited until  the  ice  again  comes  and  ends  the  work.  Or,  perhaps, 
in  the  nebulae,  10,000  or  20,000  years  would  not  be  long  enough 
to  make  changes  prominent  enough  to  be  seen  without  a  micro- 
spectrograph.  Evolution  in  wrell-advanced  suns,  however,  could 
be  detected,  for  light  from  the  mighty  upheaval  last  year  in  the 
new  sun  in  Perseus  could  be  seen  with  the  unaided  eye.  This  was 
doubtless  an  explosion  or  collision.  Evolution  proper  is  slow. 


RADIANT     ENERGY.  ?23 

PLAN    OF   THE   PALACE   OF  THE    UNIVERSE. 

From  the  best  and  most  comprehensive  soundings  let  fall  in 
space,  it  is  thought  that  the  structure  of  suns,  planets  and  nebtfse, 
is  neither  a  sphere  nor  a  disc  shaped  like  a  bi-convex  lens ;  but 
in  form  more  like  a  watch.  The  rim,  hinges  and  stem  lie  in  that 
mighty  foundation,  the  Milky  Way,  while  the  axis  of  the  watch, 
carrying  the  hands,  corresponds  to  the  axis  of  the  cosmical  struc- 
ture, the  ends  being  the  poles  of  the  galaxy. 

If  the  entire  structure  is  in  revolution  then  the  belt  of  starry 
hosts  is  the  equator,  tending  to  expand,  while  stars  at  the  poles 
would  come  in,  still  more  increasing,  flattening  into  a  lens-shaped 
mass  of  suns. 

It  is  not  known  if  the  vast  body  is  in  rotation,  since  accurate 
astronomy  is  not  100  years  old  yet.  In  10,000  years  astronomers 
may  be  able  to  find  rotary  motion  if  it  exists. 

At  all  events,  whole  myriads  of  suns,  single,  double,  triple, 
multiple,  condense,  pile  in,  crowd  together  and  congregate  in 
that  stupendous  band,  encircling  the  entire  congeries  of  flying 
bodies.  Nebulae  mostly  gather  round  about  the  galactic  poles. 
These  are  immense  volumes  of  gas  whence  suns  are  seen  in 
evolution  in  all  stages.  But  when  complete  suns  are  developed 
they  seem  to  gravitate  in  the  direction  of  the  plane  of  the  galaxy, 
bisecting  the  cosmic  structure.  And  a  majority  of  the  first  mag- 
nitude suns  lie  somewhat  near  the  plane  of  that  mysterious  ring, 
while  our  own  modest  sun  also  is  thought  to  be  near  the  plane  of 
the  magic  circle. 

For  in  many  directions  the  suns  are  in  such  colossal  heaps 
and  depths  that  there  is  scarcely  room  for  more  on  graphic  plates. 
The  distance  between  each,  however,  is  doubtless  as  great  or 
greater  than  that  separating  our  sun  from  its  neighbors — 25 
trillion  miles — except  in  the  case  of  binaries  or  close  clusters. 


224.  RADIANT     ENERGY. 

DISTANCE  OF  OUR   NEAREST   NEIGHBORS. 

Man  has  no  hope  of  ever  being  able  to  measure  the  distance 
of  more  than  a  few  near-by  stars.  Nothing  can  be  had  thinner 
than  a  spider  web,  and  it  would  not  be  possible  to  use  a  finer  in 
micrometer,  if  such  a  fiber  should  be  found.  Unless  new  dis- 
coveries or  more  accurate  measurements  in  the  line  of  sight  by 
new  spectroscopes  of  unheard-of  power,  or  by  some  undiscovered 
device  in  photometry,  the  vast  distances  of  more  than  perhaps 
50  to  loo  stars  will  never  be  known,  because  the  base  line,  the 
diameter  of  the  earth's  orbit,  186,000,000  miles,  is  so  minute  as 
to  escape  detection  in  any  microscope,  placed  on  the  distant  stars. 
Unless,  indeed,  some  incredibly  large  objective  corrected  for 
graphic  waves  should  be  constructed,  and  sensitive  plates  with 
much  finer  grain  than  silver  salts,  to  store  almost  insensible  images 
of  faint  stars  and  make  perceptible  the  still  more  minute  displace- 
ments among  the  tiny  points  due  to  the  annual  swing  of  the  earth. 
For  the  entire  area  enclosed  by  the  orbit  of  the  earth  as  seen 
from  some  of  the  stars  would  be  hidden  by  a  particle  in  a  micro- 
scope placed  on  these  stars  and  looking  this  way,  comparable  in 
size  with  the  particles  of  black  pigment  in  this  ink.  An  astron- 
omer on  Neptune  could  measure  the  distances  of  more  stars,  for 
his  base  line  would  be  in  length  5,580,000,000  miles,  and  might 
be  detected  in  a  micrometer  placed  at  not  extravagant  ste'lar 
distances. 


RADIANT     ENERGY. 


225 


Here  is  a  table  of  parallaxes  and  distances  of  a  few  well 
measured   stars : 

DISTANCES  OP  NEAREST  STARS. 


Paral- 

Distances 

Dist. 

Times 

Names 

laxes  in 

sun's 

in  trill- 

in years 

of 

seconds 

distance 

ions 

for  light 

Stars. 

of 

being 

of 

to  reach 

Arc. 

i. 

miles. 

the  earth. 

Alpha  Centauri 

0.75 

275,000 

25 

4.26 

61   Cygni            .  .  . 

.    O   4^ 

4^8,000 

4^ 

7.20 

t^.  J  *_/  y  VW^  \-S 

T"O 

/ 

Sirius 

.0  78 

^42,800 

^O 

8.  so 

Procyon    . 

_»  .  ^kJ 

O   27 

Jnr    >*—'^-/v-' 
764,OOO 

«j 

71 

•*   o^ 
12.  OO 

/  '-'•TJ'-' 

/ 

Altair 

.  .  .  O   2O 

I,O7I,72£; 

Q4- 

16.00 

O2  Hridani 

.O    IQ 

'     O     >O     J 

1,085,600 

ixt 

IOO 

17.00 

1830  Groombridge 

.  j.y 
O    17 

1,^86,6^0 

147 

/ 

2^.00 

Veea 

O    12 

?  O           '      «_/ 

1,718,000 

i  / 

158 

J 

27.00 

Aldebaran 

O    IO 

?/   •1*^/Jj7v*v' 

2  062.26=; 

o 
IQI 

/ 

72.  OO 

Capella 

O    IO 

-i-  j  \  ^  \-/  ^^  j  ^i-  V-'  J 

2,062,265 

.7 

IQI 

o 
72.  OO 

Polaris 

O    O7 

2  04.6  64.O 

y 

276 

o 

47.OO 

Arcturus    . 

.  .O.O2 

.'i/T-^'^T^ 

io,^n,2i;o 

/ 
Q^O 

TV 
I6O.OO 

This  is  an  impressive  display  of  facts  and  figures.  Thus 
the  nearest  star,  Alpha  Centauri,  is  brighter  than  the  standard 
first  magnitude  Aldebaran,  while  the  next  nearest,  61  Cygni,  is 
only  of  the  fifth  magnitude,  requiring  a  clear,  dark  night  to  see  it 
without  a  lens.  Sirius,  the  most  brilliant  star,  is  just  twice  as  far 
away  as  the  nearest. 

Look  at  the  vast  distance  of  the  pole  star — 276  trillion  miles 
— and  the  colossal  Arcturus.  How  approach  this  majestic  sun 
with  human  speech?  It  pours  forth  6,200  times  the  quantity  of 
light  emitted  by  our  little  sun.  Many  astronomers  have  despaired 
of  ever  finding  its  distance,  but  in  very  recent  years  the  mighty 
problem  has  been  attacked  with  renewed  energy,  patience  and 
skill,  notably  by  Dr.  Elkin.  Astronomers  are  agreed  that  its 
parallax  is  about  the  one-fiftieth  (i-5oth)  of  a  second.  That  is, 
go  to  Arcturus  and  look  this  way  with  the  most  powerful  microm- 


226  RADIANT     ENERGY. 

eter  made,  and  the  distance  from  the  earth  to  the  sun — 93,000,000 
miles — would  occupy  one-fiftieth  of  a  second  in  the  sky. 

Take  a  child's  marble  one  inch  in  diameter  to  a  distance  of 
161  miles,  and  it  will  appear  to  fill  one-fiftieth  of  a  second  as  an 
arc  of  a  circle.  And  modern  astronomers  must  measure  such 
quantities  as  these  or  remain  ignorant  of  the  dimensions  of  that 
part  of  the  universe  close  by  home. 

But  the  mighty  sun  Canopus — go  to  it,  turn  and  look  this 
way ;  the  distance  from  the  earth  to  the  sun  is  absolutely  invisible 
in  any  microscope  that  human  hands  can  ever  hope  to  make. 
Canopus  is  brighter  than  Arcturus ;  and  a  line  93,000,000  miles 
long,  as  seen  from  Canopus,  is  less  than  the  diameter  of  a 
spider's  web. 

But  great  things  are  now  being  done  by  photographing  the 
heavens,  and  then  measuring  the  inconceivably  small  displace- 
ments of  the  stellar  points  with  a  high-power  microscope,  under 
a  system  of  rectangular  co-ordinates,  also  photographed  in  small 
squares,  like  cross-ruled  paper. 

The  stars  are  graphed  by  a  long  exposure,  and  then  fine 
crossed  lines  are  graphed  on  the  same  plate  by  a  second  exposure, 
and  numbered.  Thus  any  star  can  be  found  as  well  as 
a  house  in  a  city  block.  The  plates  are  measured  under  a  micro- 
scope in  a  measuring  engine,  and  if  any  displacements  are  noted 
in  subsequent  graphs  the  amount  is  determined. 

Thus  parallaxes  of  the  stars  are  now  found  by  machinery 
instead  of  by  the  old-fashioned,  laborious  and  tedious  methods. 

A  most  extensive  series  of  measures  is  now  being  made  at 
Harvard  College  Observatory — notably  by  Mrs.  Fleming  and  Miss 
Maury,  the  collection  of  plates  now  numbering  more  than  1 10,000. 
A  succession  of  important  results  has  followed,  for  proper  mo- 
tions of  stars  have  been  discovered,  also  variables,  and  new  stars 
as  well.  The  photograph  is  revolutionizing  all  departments  of 
practical  astronomy,  for  Professor  Pickering  and  his  skilled  as- 


RADIANT     ENERGY. 


227 


sistants  at  Harvard  and  Arequipa,  graph  the  entire  heavens,  once 
each  month !  He  superposes  subsequent  graphs  by  months,  so, 
if  any  star  has  moved,  it  will  be  instantly  noticed,  for  their  images 
on  the  two  plates  under  the  microscope  will  not  exactly  coincide. 


Cut  88.     Double  Cluster  in  Perseus. 


Some  regions  in  the  sky  are  rich  in  stars,  and  an  idea  of  the  power 
of  modern  instruments  may  be  had  in  cut  88,  the  double  cluster 
in  Perseus,  where  no  separate  stars  appear  to  the  unaided  eye. 

All  are  familiar  with  the  Seven  Stars  or  Pleiades.    With  i?h. 
3om.  exposure  on  nine   (9)   nights,  a  region  round  about,  four 


223  RADIANT     ENERGY. 

square  degrees  in  area,  shows  almost  7,000  stars  on  the  plate.  The 
stars  often  gather  in  clusters,  as  may  be  seen  in  cut  88. 

The  Perseid  cluster  is  made  up  of  fine  stars — many  regions 
in  the  Milky  Way  are  hundreds  of  times  finer — as  in  cut  89.    Cut 


Cut  89.    Photograph  of  Milky  Way,  taken  at  Sydney,  Australia. 

89  is  of  a  photograph  of  a  rich  region  of  stars  in  the  Milky  Way, 
taken  at  Sydney,  Australia,  all  of  which  were  condensed  and 
broken  up  from  one  mass  of  primordial,  ultra-gaseous  corpuscles 
— "bodies  much  smaller  than  'atoms.'  " 


RADIANT     ENERGY.  229 


XXXIII. 
BINARY   SUNS. 

"It  is  thus  by  an  alternative  waking  and  rest,  that  the  immutable 
Being  causes  to  revive  and  die  eternally  all  existing  creatures,  active  and 
inert." — From  Laws  of  Manu,  book  i,  Shloka  50,  Hindu. 

Herschel  in  his  life-long  and  tireless  search  for  stellar  parall- 
axes, not  one  of  which  was  he  ever  able  to  find,  owing  to  his  lack 
of  accurate  micrometers,  and  knowledge  of  the  exact  value  of 
refraction  of  light  in  the  earth's  air — nevertheless  made  another 
discovery  almost  equally  important — binaries.  These  are  where 
two  suns  revolve  around  their  common  center  of  gravity,  in  regu- 
lar orbits,  nearly  always  ellipses.  And  their  study  has  greatly 
expanded  all  concepts  of  the  sidereal  universe  and  its  ancient 
history  of  evolution.  So  surprising  have  been  the  results  of  this 
investigation,  that  modern  astronomers  are  amazed  at  the  work 
of  their  own  hands,  while  the  ablest  now  living  would  have 
thought  them  beyond  human  powers,  had  they  been  predicted 
fifty  years  ago.  The  revelations  due  to  binary,  triple  and 
multiple  suns  should  be  understood  by  all  who  admire  nature 
or  who  care  to  know  what  the  brain  of  man  is  really  capable  of 
doing  in  this  age  of  trained  research.  As  soon  as  the  two  Her- 
schels,  Struve  and  other  astronomers  found  that  vast  incandescent 
suns  were  in  revolution  around  each  other,  or  rather  around  gravi- 
tational centers,  world-wide  interest  was  at  once  awakened  and 
many  skilled  observers  began  extensive  series  of  most  precise  meas- 
urement. 


RADIANT     ENERGY. 


Cut  90.    Binary  —  BC  —  of  the  triple  Sun  Gamma  Andromeda. 
Positions  From  1842  to  1897. 


Gamma  Andromeda  is  a  triple  sun,  the  largest  star  being 
A,  the  next  B,  and  the  faintest  C.  The  star  B  is  shown  at  B  in 
cut  90,  while  all  the  black  dots  are  positions  of  the  star  C,  meas- 
ured from  1842  to  1897 — 55  years.  The  star  A  is  10  seconds 
of  arc  distant  from  B,  and  is  not  shown  in  cut  90,  for  a  distance  of 
10  seconds,  small  as  it  is,  would  be  too  large  to  appear  in  this 
wondrous  diagram,  where  the  length  of  the  scale  below  is  only 
half  a  second. 

A  sphere  one  inch  in  diameter  to  subtend  half  a  second  must 
be  at  a  distance  of  6~/2  miles.  The  black  spots  are  nearer  the  mark 
than  rifle  shots  by  an  expert.  These  small  errors  were  not  so 
much  in  the  micrometer  as  in  the  earth's  air.  The  network  of 
angles  from  dot  to  dot  has  been  solved,  and  the  result  is  the  curved 
line,  I,  3,  2,  a  very  eccentric  ellipse,  the  mathematical  orbit  of  the 
star  C  around  B,  or,  strictly,  around  the  center  of  gravity  of  B  and 
C,  for  B  also  traverses  a  minute  ellipse  the  same  in  shape  of  that 
moved  over  by  C,  once  in  55  years.  The  letter  C  does  not  ap- 
pear, it  may  be  imagined  to  be  anywThere  on  the  ellipse,  i,  3,  2. 

It  will  be  noticed  how  eccentric  the  orbit  is,  that  is,  its  devia- 
tion from  a  circle,  which  is  0.82,  while  that  of  the  orbit  of  the 


RADIANT     ENERGY.  231 

earth  around  the  sun  is  0.017,  only  one-fifth  as  great.  The  con- 
sequence is  that  when  the  flying  sun  C  moves  from  I  to  2,  around 
B,  in  the  direction  of  the  arrows,  it  moves  with  great  speed  to 
prevent  falling  on  B,  while  the  velocity  is  slow  at  3,  far  away. 
The  nearest  approach  to  B  is  called  periastron,  while  the  most 
remote  position  is  apastron. 

This  binary  has  just  made  one  circuit  since  discovery,  and 
five  years  on  another.  The  two  stars  B  and  C  do  not  revolve 
around  A,  the  large  star,  10  seconds  away,  so  far  as  detected,  but 
they  all  move  in  the  same  direction,  side  by  side,  through  space, 
which  movement  of  stars  is  called  proper  motion.  The  star  C 
passed  periastron  in  1892. 

It  is  not  necessary  to  watch  a  binary  through  a  complete 
revolution,  for,  give  an  arc  of  an  ellipse  to  a  geometer  and  he  can 
compute  the  entire  curve.  And  some  of  the  times  of  revolution 
are  known  to  be  more  than  1,000  years. 

Human  beings  could  not  live  on  the  planets  revolving  around 
either  of  these  suns,  B  and  C.  For  when  C  came  near  B  the 
inhabitants  would  be  between  the  suns — and  there  would  be  no 
night.  All  water  would  be  boiled  into  steam  and  life  expire.  As 
periastron  approached,  the  people  on  worlds  round  about  sun  C 
would  notice  sun  B  growing  rapidly  larger.  And  then  larger 
and  hotter  still,  and  the  heat  and  light  would  soon  become  intol- 
erable. 

Milton's  concept  of  living  beings  chained  to  incandescent, 
porphyritic  stone,  would  fail  here.  The  planetary  heavens  would 
burn  as  heated  brass,  and  the  heats  of  Pelee  and  Souftriere  would 
pale  and  faint.  The  surfaces  of  the  inhabited  worlds  would  be- 
come parched,  cracked  and  seamed — steam,  smoke  and  deadly  gas 
would  fill  the  suffocating  air. 

People  near  sun  B  would  behold  C  rushing  through  their 
torrid  sky  with  frightful  speed,  growing  larger  and  hotter  every 
minute,  and  the  sinister  sun  would  appear  in  most  portentous 


232  RADIANT     ENERGY. 

aspect.  For  a  world  happening  to  be  between  the  suns,  rapid 
death  would  fall  on  plant,  animal  and  man,  or  a  still  higher  type. 
The  eventful  day  of  periastron  would  occur  every  55  years.  It 
is  doubtful  if  life  can  be  on  worlds  about  suns  whose  orbits  have 
eccentricities  greater  than  one-half,  for  even  then,  the  variation 
in  heat  would  be  tremendous.  The  distance  of  the  system  of 
Gamma  Andromeda  is  unknown. 

ALPHA  CENTAURI. 

This  majestic  pair  of  suns,  our  nearest  neighbor,  revolves  in 
8 1  years.  The  eccentricities  of  their  orbits  are  one-fifth,  so,  beings 
with  no  more  intelligence  than  men  might  adapt  themselves  to  the 
great  variations  of  climate. 

FINDING  MASS  OF  BINARY  SUNS. 

Kepler  discovered  one  of  the  most  stupendous  laws  that  the 
brain  of  man  has  yet  detected  in  the  hidden  recesses  and  labyrinths, 
dim  corridors,  obscure  passages  and  caves  under  nature.  This 
law  rules  all  that  fraction  of  the  sidereal  edifice  near  enough  to 
be  seen  in  telescopes,  however  powerful. 

Law :  The  squares  of  the  times  of  revolution  of  bodies 
around  their  common  center  of  gravity  are  to  each  other  as  are  the 
cubes  of  their  mean  distances  from  their  center  of  motion. 

Application  of  Law :  The  time  required  for  the  earth  to 
revolve  around  the  center  of  gravity  of  the  earth  and  sun  is  equal 
to  one  (i),  and  the  earth's  distance  from  that  center  equals  one 
(i).  The  observed  time  for  Jupiter  to  make  circuit  is  equal  to 
11.86.  Now  11.86  squared  is  140;  and  the  cube  root  of  140  is 
5 . 2,  but  that  is  the  known  distance  of  Jupiter  from  the  sun,  found 
in  other  ways.  That  is,  Jupiter  is  5 . 2  times  farther  from  the  sun 
than  the  earth  is,  or  483,000,000  miles.  This  law  enables  men  to 
tell  the  quantity  of  matter  in  suns,  so  far  away  that  the  mind  is 
unable  to  form  any  concept  of  the  distance. 


RADIANT     ENERGY.  233 

A  quantity  of  matter  equal  to  that  in  the  sun  and  earth  com- 
bined is  by  the  action  of  gravity  able  to  force  a  body  at  the  earth's 
distance  from  the  sun  to  go  around  it  in  365^4  days  to  prevent 
falling  into  the  sun,  for  the  centrifugal  tendency  equals  gravity. 

Since  gravity  depends  on  quantity  of  matter,  or  mass,  it  is 
clear  that  there  must  be  a  strict  relation  between  the  motion  of 
the  earth  and  the  sun  and  between  the  Alpha  Centauri  and  its 
revolving  sun.  The  combined  mass  of  these  two  suns  is  able  to 
force  one  of  the  suns  at  a  distance  from  the  most  massive,  21.33 
times  as  great  as  that  of  the  earth  from  the  sun,  to  revolve  around 
it  in  Si  years  to  prevent  falling.  Then  the  distance,  21.33  cubed, 
equals  9,664,  while  81  squared  is  6,561,  and  the  quotient  of  these 
numbers  is  1,5,  so  the  quantity  of  matter  in  both  suns  is  known 
to  be  one  and  a  half  times  greater  than  that  in  our  sun  and 
earth.  Since  the  mass  of  the  earth  amounts  to  nothing — almost — 
it  is  said  the  suns  in  the  Centaur  are  ij^  times  more  massive  than 
ours.  Their  distances  apart — 21.33 — is  obtained  from  the  appar- 
ent semi-major  axis  of  the  orbit,  which  is  16  seconds  of  arc.  This, 
divided  by  the  parallax,  0.75  of  a  second,  equals  21.33  times 
93,000,000  miles,  equals  1,984,000,000  miles,  a  little  more  than 
our  planet  Uranus  from  our  sun.  Thus  given  three  quantities  the 
distance  to  these  two  suns — twenty-five  million  million  miles — 
their  distance  apart,  21.33  times  greater  than  that  of  the  earth 
from  the  sun,  and  their  time  of  revolution — 81  times  greater  than 
that  of  the  earth — then  the  finding  of  their  combined  mass  is  a 
mere  question  of  arithmetic.  But  it  took  120  years'  severe  labor 
to  find  the  distance,  and  it  took  Kepler  17  years'  unheard-of  work 
to  find  his  mighty  law. 

Cut  91  shows  the  orbit  of  the  binary,  Alpha  Centauri. 

THE  SUN   SIRIUS. 

About  fifty  years  ago  it  was  found  that  the  regular  motion 
of  that,  to  us,  brightest  of  stars,  Sirius,  was  disturbed.  Instead  of 


234- 


RADIANT     ENERGY. 


traversing  a  regular  curved  line  on  an  ellipse,  or  a  straight  line 
through  space,  clue  to  our  own  proper  motion,  it  deviated  first  to 
one  side  and  then  to  the  other.  It  was  watched  with  interest  by 
many  astronomers.  They  all  agreed  that  the  perturbation  was 
caused  by  either  a  small  sun  revolving  around  it  or  a  dark  world. 
Auwers  then  applied  that  mighty  power,  mathematics,  computed 
the  orbit  of  the  unseen  body,  and  told  its  direction  from  Sirius. 
And  then  A.  G.  Clark  discovered  it  in  exactly  the  predicted  place 
with  his  new  telescope,  now  in  the  observatory  at  Evanston,  Ills. 


**• 
<s\ 

*> 

t^ 

^ 

0> 

^X^ 

v^ 

V- 

^^ 

,     ^ 

^v 

»t 

*6^- 

\ 

ht 

,*    * 

Cut  91     Orbit  of  Our  Nearest  Neighbor,  Alpha  Centauri.     Period    81  Years. 

This  was  the  beginning  of  that  great  branch,  the  "Astronomy  of 
the  Invisible."  The  new  body  proved  to  be  a  small  sun,  for  it 
shines  by  its  own  light,  where  planets  are  seen  only  by  borrowed 
radiance. 

MASS   OF    SIRIUS   AND    ITS    COMPANION. 

For  several  years  the  parallax  of  Sirius,  as  determined  by 
Professor  Gill,  has  been  adopted  as  0.37  second  of  arc ;  but  now 
comes  W.  S.  Adams  with  a  spectroscopic  parallax  of  0.21  second 
(the  mean  of  these  is  0.29  second),  and  with  this  let  the  mass  of 
both  suns  be  computed.  A  radian — 206,265  seconds — divided 
by  0.29  second  equals  700,000.  That  is,  Sirius  is  700,000  times 
farther  from  the  earth  than  our  sun  is. 


RADIANT     ENERGY. 


235 


in  cut  92  is  shown  Professor  N.  M.  Mann's  carefully  com- 
puted orbit,  and  its  semi-major  axis  is  given  by  him  as  seven 
seconds  (Newcomb  gives  five  seconds),  which  is  the  apparent 
value  seen  from  the  earth;  the  real  value,  being  seven,  divided  by 
0.29,  equals  24;  thus  the  companion  is  24  times  farther  from 
Sirius  than  our  sun's  companion,  the  earth,  is  from  it.  Kepler 
to  the  rescue,  for  the  distance,  24  cubed,  is  13,824,  and  the  time, 
50  years,  squared  equals  2,500,  the  quotient  of  the  two  numbers 
being  5.5,  so  the  quantity  of  matter  in  Sirius  and  its  neighbor  is 


Cut  92.     Orbit  of  Sirius. 

$l/2  times  that  in  our  sun  and  earth.  If  the  value,  five  seconds, 
as  given  by  Professor  Newcomb,  had  been  used,  the  mass  would 
have  come  out  smaller,  for  less  matter  would  be  required  to  cause 
the  small  sun  to  make  circuit  around  Sirius  at  a  less  distance  in 
the  same  time. 

The  error  is  less  than  those  made  in  shooting  at  the  Harvey- 
ized  steel  targets  in  the  navy-yards.  Life  cou'.d  not  exist  a  min- 
ute on  planets  around  the  revolving  sun,  even  when  at  its  mean 
distance  of  1,232,000,000  miles,  or  less  than  that  of  Uranus 
ii  om  the  sun. 

There  are  over  200  telescopic  binaries  known — that  is,  widely 


236  RADIANT     ENERGY. 

separated  suns — whose  distances  apart  are  great  enough  to  be 
seen  in  the  best  telescopes.  But  new  and  more  magnificent  arrays 
of  splendid  binary  and  ternary  suns  are  shown  in  the  spectroscope. 
Here  is  a  table  of  short-period  telescopic  binaries : 

Periods 
Names  of  Suns.  in  years. 

Kappa  Pegasi   1 1 . 42 

Delta  Equulei   1 1 .45 

883   Burnham    1 5 . 80 

XI  Sagittarii 18.85 

Rho  Argus    22.00 

85  Pegasi 24.00 


From  these  short  periods  of  revolution,  the  times  extend  to  as 
high  as  1,500  years.  Thus,  from  Professor  W.  J.  Hussey's  cata- 
logue, Lick  Observatory,  these  periods  are  taken  at  random:  135, 
200,  115,  118,  93,  182,  190,  107,  260  and  198  years,  while  the 
star  Zeta  Aquarii  is  1,500  years. 

Some  astronomers  devote  their  entire  life-work  to  double 
stars ;  thus  Professor  S.  W.  Burnham  devoted  thirty  years  to  this 
great  work  and  discovered  1,290  close  stars,  while  Professor  W. 
J.  Hussey  has  discovered  many  and  remeasured  all  those  dis- 
covered by  Russian  astronomers. 

Prominent  among  them  are  the  stars  Gamma  Andromeda,  as 
shown  in  cut  90.  The  maximum  distance  between  the  compo- 
nents was  in  1877,  0.84  second.  At  this  writing  they  are  less 
than  half  a  second,  and  scarcely  visible  as  two  points  in  the  Lowe 
i6-inch  telescope,  if  at  all. 

The  two  dots — large  suns,  however — of  Gamma  Andromeda, 
look  like  one  in  anything  but  a  large  telescope.  And  the  larger 
the  object-glass  and  the  higher  the  power  of  the  eye-piece  the 


RADIANT     ENERGY. 


237 


Cut  93.      Barnard's  Milky  Way. 

wider  is  the  black,  infinite  space  between.  This  is  called  separat- 
ing or  magnifying  power,  but  not  a  solitary  star  in  the  celestial 
vault  can  be  magnified  by  any  instrument  men  can  make ;  their 
distances  are  so  stupendous  that  they  all  look  like  minute  points 
What  the  telescope  does  is  to  bring  millions  more  into  view. 
Planets  near  home  are  all  magnified  into  wide  discs. 

Of  all  telescopic  binaries,  perhaps  sixty  orbits  have  been  com- 
puted with  varying  degrees  of  accuracy,  measures  being  as  diffi- 


238  RADIANT     ENERGY. 

cult  as  any  dealt  with  by  astronomers.  But  binaries  capable  of 
detection  by  telescope  are  few  indeed  compared  to  the  vast  num- 
ber now  being  discovered  by  that  all-powerful  and  marvelous  in- 
strument, the  tele-spectroscope. 

Thus  space  contains  countless  suns,  revolving  around  their 
centers  of  motions  with  great  speed.  Many  millions  of  these 
may  be  surrounded  by  cool  worlds,  each  inhabited  by  beings  for 
more  exalted  in  mental  power  than  the  human  animalculse. 


RADIANT     ENERGY. 


239 


XXXIV.  z. 

DISCOVERY  OF  SPECTROSCOPIC   BINARIES. 

"The  universe  is  a  unique,  perfect  and  spherical  production,  since 
the  sphere  is  the  most  perfect  of  figures ;  animated  and>  endowed  with 
reason,  since  that  which  is  animated  and  endowed  with  reason  is  better 
than  that  which  is  not." — Timaeus  of  Locris. 

The  binaries  mentioned  in  XXXIII  were  all  discovered  by 
means  of  the  telescope,  measured  with  micrometer,  and  their 
masses  computed  by  gravitational  methods ;  that  is,  by  Kepler's 
laws.  But  the  detection  of  vast  suns  revolving-  around  their  mass 
centers  in  space  at  once  awakened  the  keenest  interest.  These  re- 
condite researches  were  made  with  the  spectrograph — a  modified 
form  of  spectroscope  attached  to  the  greatest  telescopes.  Their 
discovery  was  made  possible  by  an  abstruse  law  of  wave  motion 
known  as  Doppler's  principle,  by  which  if  a  light  source  comes 
toward  or  recedes  from  the  observer,  its  velocity  can  be  found. 


Cut  94.     Doppler's  Effect.     A  and  B  are  luminous  points,  emitting  waves  in  the 
direction  S.     While  waves  move  from  A  to  S,  B  moves  from  X  to  B. 

Cleared  in  cut  94,  where  A  is  a  source  or  light  at  rest.  To 
its  right  are  eight  waves  moving  to  S,  while  B  also  is  a  light 
source,  and  was  formerly  at  X.  Let  both  waves  enter  the  slit 
of  a  spectroscope,  S,  at  the  same  time. '  While  light  was  moving 
from  A  to  S  the  source  of  waves,  B,  moved  from  X  to  B,  over 


240  RADIANT     ENERGY. 

space  equal  to  one  wave-length.  Then,  since  the  velocity  of 
light  does  not  change,  it  is  evident  that  the  light  waves  will  be 
crowded  into  the  space  properly  occupied  by  seven  normal  undu- 
lations. That  is,  each  will  be  one-eighth  shorter.  This  is  a  bed- 
rock fact  in  nature,  and  leads  to  the  most  wonderful  deductions. 
All  along  in  this  series  it  has  been  shown  that  the  shorter  the 
waves  the  greater  is  their  refrangibility,  or  property  of  being  bent 
aside  out  of  their  course  by  refraction  of  a  prism  or  diffraction  of 
a  grating.  Violet  is  bent  the  most  and  red  the  least,  for  violet 
vibrates  nearly  twice  as  fast  as  red,  therefore  its  waves  are  slightly 
more  than  half  as  long  as  red.  Whence  the  fact  stands  out  that 
the  place  of  a  color,  or  if  this  is  absorbed,  a  line,  in  the  spectrum 
is  determined  solely  by  its  wave-length. 


Cut  95.    White  I^ight  (Fig.  1)— Passing  through  a  prism,  P.     Fig.  2  Resulting  displace- 
ment spectrum  shown  in  dotted  lines. 

This  is  cleared  in  cut  95,  where  white  light  is  entering  a  prism 
as  a  band  and  emerging  as  a  wide  spectrum,  the  violet  being 
deflected  aside  the  most,  in  figure  I. 

Basic  Law :  If  a  source  of  light  is  approaching,  the  lines 
in  its  spectrum  are  displaced  toward  the  violet;  if  receding,  the 
lines  shift  toward  the  red. 

With  breathless  interest  let  the  powerful  spectroscope  be 
turned  full  on  the  stars,  and  see  what  will  appear! 

Behold !     The  spectra  of  many  stars  actually  show  displace- 


RADIANT     ENERGY. 


24.1 


ment,  now  toward  V,  and  then  to  R,  as  shown  by  the  dotted 
lines  in  figure  2,  cut  95. 

Human  skill  is  taxed  to  the  utmost  in  these  delicate  re- 
searches. The  slit  of  the  spectrograph  is  exceedingly  minute,  and 
the  great  driving  clock  moving  the  giant  telescope  must  keep  up 
with  the  rotation  of  the  earth  with  extreme  accuracy.  The  entire 


Cut  96.     The  Mills'  Spectrograph  in  the  lyick  Observatory — cover  off. 

spectrograph  must  be  kept  at  the  same  temperature  throughout 
the  long  exposure  of  the  sensitive  plate.  This  is  accomplished 
by  inclosing  the  entire  instrument  in  a  non-conducting  envelope 
and  keeping  the  interior  at  a  constant  temperature  by  means  of 
electric  resistance  coils. 

All  this  is  shown  in  cut  96,  the  now  famous  Mills  spectro- 
graph in  the  Lick  Observatory. 


242 


RADIANT     ENERGY. 


Cut  96A.     Mills'  Spectrograph,  enclosed  in  constant  temperature  case. 


Professor  W.  W.  Campbell,  with  this  instrument,  has  wrested 
the  most  reluctant  secrets  from  the  universe  and  told  the  motion 
of  suns,  brought  unknown  binaries  and  distant  systems  of  suns  in 
revolution  to  the  gaze  of  astonished  man.  The  complex  mechan- 
ism in  the  upper  and  right  hand  part  of  cut  96  is  the  end  of  the  36- 
inch  equatorial.  The  Spectrograph  is  inclosed  in  thick  woolen 
cloth.  The  box  is  of  cedar,  and  its  cover  is  seen  on  the  floor. 
The  little  tube  is  the  guiding  telescope  to  center  the  apparatus,  and 
looks  down  on  the  train  of  prisms ;  while  above  is  a  window 
through  which  the  micro-thermometer,  sensitive  to  one-twenty- 


RADIANT     ENERGY. 


243 


Cut  96B.     Mills'  Spectrograph  without  case. 


fifth  degree,  is  read.  The  great  object-glass — 36-inch — far  above, 
receives  lights  from  suns,  sends  it  through  the  tiny  slit,  one-thou- 
sandth of  an  inch  wide,  and  prisms  to  the  spectro-camera, 
where  the  wondrous  graphs  are  secured,  telegrams  from  suns  so 
distant  that  the  mighty  void  between  cannot  be  measured. 

Cut  966  is  the  Mills-graph  before  the  case  for  regulating 
temperature  was  added. 

There  are  other  spectrographs  in  the  world,  notably  that  of 
Vogel,  in  Potsdam,  Germany,  but  none  have  dragged  forth  mys- 
teries more  arcane  than  the  Mills  graph. 


244-  RADIANT     ENERGY. 

MOTION    OF    STARS   IN    THE    LINE    OF    SIGHT. 

Many  suns  are  thus  seen  to  be  approaching,  and  as  many  re- 
ceding with  varying  speeds,  all  rapid.  The  star  must  approach 
or  recede  on  a  straight  line  for  motion  to  be  detected,  for  side- 
wise  motion  cannot  be  seen  in  a  spectroscope,  since  it  does  not 
change  wave  lengths. 

Doppler's  law  can  be  proved  by  any  one  who  will  stand  by  a 
railway  when  an  express  is  coming,  if  the  bell  or  whistle  sounds. 
If  approaching,  the  key  note  rises,  for  more  waves  enter  the  ear, 
while  after  the  train  passes,  the  note  falls. 

Approaching.  Receding. 

Miles  per  second.  Miles  per  second. 

Alpha    Arietis    12     Aldebaran    31 

Gamma   Leonis    25     Betelgeuse    18 

Spica   ii     Rigel     14 

Altair    24     Capella    30 

Polaris    12     Alpha  Coronae   20 

61    Cygni    27     Regnlus    — . 

Procyon    7     Eta  Pegasi   3 

Arcturus    5     XI  Piscium   19 

Beta  Herculis 30     Epsilon    Hydrse    30 

Sirius    5 

In  cases  of  binaries  moving  in  the  line  of  sight  the  motions 
given  are  those  of  the  center  of  mass,  around  which  both 
revolve.  Combining  quite  a  number  of  cases,  and  taking  their 
mean,  it  appears  that  the  velocity  potential  to  or  from  the  earth 
is  about  16  miles  per  second,  the  speed  of  the  earth  on  its  orbit 
being  18^2  miles  per  second.  Below  is  a  table  giving  periods 
of  revolutions  of  binaries,  discovered  by  means  of  the  spectro- 
scope, together  with  their  orbital  velocity  in  miles  per  second. 


RADIANT     HNHRGY. 


SPECTROSCOPIC   BINARIES. 


24-5 


Orbital 

Velocities 

Periods. 

Miles  per 

Names  — 

Days. 

Second. 

Mu  Scorpii  

1-45 

144.0 

Pi  Scorpii 

I    S7 

L  '  j/ 

Delta  Orionis  

1-91 

44-5 

Beta  Persei   

2.87 

25-8 

Castor  (i)    

2.91 

7.0 

A.  G.  C.,  10,534  

3-I2 

190.0 

Beta  Aurigse  

3.98 

75-o 

Pole  Star   

3-98 

2.O 

Spica   

4.01 

57-o 

Delta  Cephei  

5.37 

13.0 

Eta    Aquilse    

7.18 

13-4 

Zeta  Centauri 

8  02 

Zeta   Geminorium    

14-15 

8.2 

Iota   Pegasi    

IO.20 

30.0 

Beta   Lyrse    

12.91 

113.0 

Xi  Leonis   

H-IS 

35-0 

Lambda  Andromeda 

20  .  OO 

5-o 

Capella    

.  .  .  .      IO4.00 

16.0 

Beta  Herculis  

....      412.00 

8.0 

Chi  Draconis    

282  .  oo 

II.  0 

Eta  Pegasi  

8l8.00 

9.0 

Beta    Canricorni 

.  T.OOO.OO 

This  is  a  remarkable  range  in  time  and  velocity,  from  45 
hours  to  three  years,  and  from  two  to  190  miles  per  second.  So 
vast  is  the  distance  of  Polaris  that  an  error  is  easily  made  in 
bringing  out  its  speed  only  two  miles. 


246  RADIANT     HNHRGY. 

Not  one  of  these  stars  would  ever  have  been  known  as  bina- 
ries without  the  spectroscope,  for  no  telescope  could  be  made  to 
see  them  double  (they  look  like  a  point)  with  any  magnifying 
power.  And  their  spectra  are  all  photographed,  so  that  in  the 
future,  should  changes  occur,  they  will  be  seen. 


+++++++++++•»++++++»»»»»*»• 

CUT  97— ORBIT  OF     A   BINARY     SUN 
HIGHLY  ECCENTRIC. 


DETECTION    OF    BINARIES. 


Call  A  and  B  two  suns,  so  close  that  no  telescope  could  sepa- 
rate them;  but  let  them  actually  be  revolving  as  shown 
in  the  orbit,  cut  97.  When  the  sun  of  less  mass  is  at  A  it  is  re- 
ceding from  the  earth,  and  approaching  with  greatly  increased 
speed  when  it  moves  around  in  the  direction  of  the  arrows  to  13. 
The  lines  of  sight  to  the  earlh  are  parallel  as  shown,  no  matter 
how  large  the  orbit  of  any  binary  yet  discovered  may  be.  And 
waves  on  these  lines  enter  the  spectroscope  on  the  dust  particle 
called  the  earth,  as  at  S,  cut  94,  and  displacement  is  measured. 
And  the  velocity  of  approach  or  recession  can  be  computed  by 
mathematical  formulas  or-  determined  by  experiment. 

VELOCITIES   AND   DISPLACEMENT. 

In  cut  98  let  S  be  the  sun  and  E  the  earth,  while  A  and  B 
represent  the  planet  Venus  at  opposite  points  on  its  orbit.  At  A 
the  planet  is  receding  from  the  earth  on  a  straight  line,  while  at 
B  it  is  approaching.  But  the  velocities  of  Venus  at  these  points 


RAD  I A  NT     ENERGY.  247 

are  known  with  great  accuracy,  so  the  value  of  displacement  of 
spectral  lines  becomes  known. 

If  an  observer  on  an  express  train,  at  one  mile  per  mTnute, 
travels  toward  the  star  Vega  for  100,000,000  years,  and  takes  a 
powerful  telescope — the  largest  made — and  a  spectrograph,  and 
should  turn  and  look  this  way,  straining  his  eyes,  he  would  see 
a  faint  and  struggling  ray  from  our  sun.  With  consummate 
skill  he  might  secure  a  spectrogram  showing  displacement.  If 
he  did,  he  would  find  the  shifting  toward  the  violet,  and  computing 
would  find  the  sun  approaching  with  a  velocity  of  twelve  miles 


Cut  98.    The  Sun,  S;  E,  the  Earth;  A  and  B,  Positions  of  the  Planet  Venus. 

per  second.  For  our  little  star — the  sun— is  moving  toward  the 
giant  Vega,  and  drags  along  its  stately  company  of  planets,  moons 
and  comets.  Our  star  is  not  a  binary ;  it  is  solitary  and  alone  in 
space.  A  ship  in  the  center  of  the  Pacific  ocean  is  not  more 
lonely.  Indeed,  not  at  all,  for  her  crew  can  speak  with  human 
kind  on  any  distant  shore  by  space  waves — soon.  For  some  on 
land  know  that  such  a  ship  exists;  but  if  the  5i,(ereal  universe  is 
filled  with  intelligent  beings,  only  professional  astronomers  have 
heard  of  the  sun,  and  none  are  aware  that  the  earth  is  in  exist- 
ence. 


RADIANT     ENERGY. 


Cut  99.     Spectrum  of  Beta  Aurigse.     Upper  Figure  showing  Displacement  of  a  I^ine. 

In  cut  99  is  shown  a  marvelous  spectrogram  of  the  binary 
sun,  Beta  Aurigse,  where  two  suns  make  revolution  in  four  days, 
with  velocity  of  seventy-five  miles  per  second.  But  what  shall  be 
said  of  Mu  Scorpii,  two  suns  rushing  with  a  terrific  speed  of  144 
miles  per  second,  making  circuit  in  forty-five  hours? 


RADIANT     ENERGY.  249 


XXXV. 

SPECTROSCOPIC  BINARIES. 

O  Thou  of  whom  all  is  the  manifestation, 

Thy  nature  is  the  spring  of  thy  being: 

Whatever  is,  is  thou ; 

We   are  all   billows   in   the   ocean   of   thy   being; 

We  are  a  small  compass 

Of  thy  manifested  nature. 

— From   Dabistan,   Vedantic   Phil.,   Hindu. 

Since  the  evolution  of  the  human  species  began,  or  since 
spoken  or  written  language  developed,  or  since  man  began  to 
think,  since  he  first  questioned  nature,  and  through  all  of  his 
devious  and  erratic  career,  whether  within  the  historic  period  or 
before,  all  achievements  wrought  by  his  hands  fall  short  of  the 
marvelous  work  recorded  in  this  chapter.  This  great  achievement 
of  the  brain  of  man  beyond  comparison  with  anything  else,  start- 
ling even  to  the  men  who  do  the  work,  is  the  vast  problem  lately 
solved  of  finding  the  masses  of  suns  without  knowing  their  dis- 
tance. 

In  chapter  thirty-four,  the  quantity  of  matter  in  suns  was 
computed  by  well-known  laws  of  mechanics,  for  in  every  case  the 
distances  from  the  earth  to  these  distant  suns  were  given.  But 
by  spectroscopic  researches  on  waves  of  light,  fully  explained 
under  the  title  "Doppler  Effect"  a  plan  was  discovered  that  bor- 
ders— one  would  think — on  the  limit  of  human  powers. 


250  RADIANT     ENERGY. 

Cut  100  shows  compressed  and  expanded  waves  from  a 
binary  sun.  The  eye  of  the  reader  should  be  imagined  to  be 
in  the  plane  of  the  paper  looking  toward  S.  Cleared 
in  cut  100,  where  S  is  a  large  sun  with  a  smaller  sun  making 
regular  revolutions  around  it  on  an  orbit  of  great  eccentricity. 
A  line  extends  from  S  in  the  direction  of  the  earth,  which  in  the 
cut  is  marked  distant  100  trillion  miles.  It  could  as  well  have 
been  200,  since  distance  has  nothing  to  do  with  the  problem,  pro- 


COMPRESSED 


TO  THE  EARTK 

100  TRILLION"  HUES  I  A 


WAVES 


Cut  100.     Orbit  of  a  Star  around  S.     Waves  that  reach  the  earth  are 
compressed  and  lengthened, 

viding  sufficient  light  can  pass  through  the  space,  whatever  i- 
may  be,  to  form  a  measurable  spectrum.  At  A  the  revolving  sun 
is  retiring  from  the  earth,  and  waves  of  light — since  neither  rates 
of  vibration  nor  velocity  of  propagation  change — must  become 
longer,  and  a  less  number  enter  the  spectroscope  each  second; 
and  become  shorter  at  B,  and  more  pass  into  the  slit.  In  Chapter 
thirty-four,  cuts  are  given  showing  that  this  change  in  wave- 


RADIANT     ENERGY.  251 

lengths  produces  lateral  shift  of  lines,  now  toward  the  red,  and 
then  toward  the  violet,  and  speeds  of  approach  and  recession 
corresponding  to  lateral  displacements  are  known,  which  knowl- 
edge leads  to  surprising  results. 

HOW  TO  WEIGH   BOTH  SUNS. 

It  will  be  understood  that  cut  100  is  a  spectroscopic  binary, 
that  is,  the  smaller  sun  whether  at  A  or  B  cannot  be  seen  in  any 
telescope,  both  suns  look  like  one,  even  in  the  4O-inch  glass. 
Their  real  distance  apart  may  be  many  million  miles,  yet  so  stu- 
pendous is  the  distance  from  the  earth  that  they  look  like  one. 
But  the  spectroscope  deals  with  waves  requiring  64,000  to  make 
one  inch,  and  can  detect  variations  in  velocity  of  the  flying  sun 
where  the  telescope  -alone  would  be  powerless.  Neither  can  the 
spectroscope  see  the  revolving  sun,  whether  at  A  or  B,  all  that 
appears  in  any  spectroscope  is  the  band  of  colors  called  the  spec- 
trum. All  that  it  does  see  in  this  case,  is  the  change  wrought 
in  lengths  of  light  waves  at  A  and  B.  But  this  is  enough  to 
enable  mathematicians  to  compute  the  quantity  of  matter  in  both. 
The  curve  around  the  large  sun  (S)  is  an  ellipse,  whose  properties 
are  known  with  rigid  accuracy.  B  is  the  periastron,  and  A  apas- 
tron,  and  velocities  at  each  are  measured.  At  A  the  speed  is 
slow,  while  at  I>  it  is  so  enormous  as  to  be  past  comprehension. 
But,  with  both  velocities,  it  is  possible  to  determine  the  average 
velocity  all  the  way  round.  And  by  watching,  the  time  of  revolu- 
tion can  be  ascertained. 

A  train  moving  6  hours  with  a  speed  of  50  miles  per  hour 
travels  300  miles. 

And  a  sun  whether  on  an  ellipse  or  circle,  moving  50  years 
with  a  velocity  of  40  miles  per  second,  describes  a  distance  de- 
termined by  simple  multiplication.  Thus  the  great  fact  now  ap- 
pears.— 


252  RADIANT     BNBRGY. 

THE   SIZE   OF   THE   ORBIT   IS    KNOWN. 

From  Kepler's  Law — see  chapter  XXXIII, — it  is  known 
how  much  matter  is  required  acting-  by  gravity,  through  any  given 
distance,  to  impart  any  given  velocity,  to  prevent  the  two  suns 
from  falling  together.  And  thus  human  genius  has  found  the 
masses  of  binary  suns  sunk  in  unfathomable  depths,  so  deep  that 
no  micrometer  can  give  any  clue  to  the  distance.  Thus  since  man 
appeared,  no  instrument,  no  concept,  no  achievement,  can  com- 
pare with  this  mighty  work. 

BETA  I.YRAE. 

This  massive  binary  presents  phenomena  of  great  interest  to 
the  spectro-physicist.  Bright  lines  are  seen  in  its  spectrum,  and 
dark  lines  at  times  are  superposed  either  over  them  or  closely 
side  by  side. 

But  the  bright  and  black  lines  oscillate  now  to  the  right  and 
now  to  the  left — toward  the  red  and  to  the  violet.  Most  accurate 
photometers  are  now  in  use.  They  measure  minute  variations  in 
the  intensity  of  light  of  variable  stars,  and  a  majority  of  binaries 
sent  out  variable  quantities  of  light.  The  3.6  mg.  star  Beta  Lyrae, 
near  the  bright  star  Vega — now  glorious  in  its  radiant  splendor, 
rising  early  these  June  evenings  in  the  northeast — is  variable. 

Watching  closely,  the  light  is  seen  to  decrease  to  a  minimum 
in  six  and  one-half  days,  and  then  the  intensity  begins  to  rise ; 
but  by  looking  carefully  with  micro-photometer  at  the  time  of 
next  minimum,  it  will  be  noticed  that  the  light  is  not  the  same 
as  in  the  first  minimum.  But  maxima  are  equal.  Here  was  a 
surprising  case,  unequal  minima  and  equal  maxima.  Renewed 
observations  were  made  by  the  ablest  astronomers,  and  none 
could  find  the  cause,  until  Professor  G.  W.  Meyers  came  to  the 
rescue. 


RADIANT     ENERGY. 


253 


The  remarkable  system  of  Beta  Lyrge  is  made  clear  by 
Meyers'  demonstration  in  cut  101.  Not  being  aware  that  Profes- 
sor Myers  has  printed  any  cut,  this  one  is  drawn  to  represent  the 
phenomena  as  described  by  him,  using  Poincare's  apioid  form  of 
sun.  The  apioid  will  be  explained  in  the  next  paper.  In  cut  101, 
a  and  b  are  two  suns,  distorted  in  shape  by  centrifugal  tendency 
due  to  rapid  revolution, — a  complete  circuit  is  made  in  13  days, — 


Cut  101.     Meyer's  Conception  of  the  Evolution  of  the  Binary,  Beta  Lyrae. 


and  by  Darwin's  tides.  Let  the  small  sun,  b,  approach  the  reader's 
eye,  and  a,  recede,  below  the  plane  of  the  paper,  both  revolving 
around  their  center  of  mass,  c.  The  side  view  as  seen  from  the 
earth  presents  the  maximum  light,  for  both  a  and  b  are  visible, — 
as  one  star,  however, — their  distance  from  the  earth  is  so  great 
as  to  forever  preclude  their  ever  being  seen  separated.  But  the 
spectroscope  measures  their  radiant  waves.  As  they  turn,  b  will 
come  betwen  the  observer's  eye  and  a.  The  small  sun  is  two  and 
one-half  times  as  bright  as  the  large.  The  combined  light  of  both 
stars  will  enter  the  spectroscope  on  the  same  straight  line,  and 
the  result  is  the  bright  minimum,  as  shown  at  c  in  the  two  con- 
centric circles  below  b. 

When  b  revolves  so  as  to  be  behind  a,  as  shown  in  the  dotted 
circle  d,  the  light  of  a  only  will  be  seen,  and  the  result  is,  a  dim 
minimum  alternating  every  6^  days.  If  both  suns  are^  ellipsoids. 


254 


RADIANT     ENERGY. 


Cut  102.     Dr.  Vogel's  Visual  Telescope  A  and  Photographic  Telescope  B 
and  Spectrograph,  2.     Potsdam,  Germany. 


RADIANT     ENERGY.  255 

— ovals — but  of  different  sizes  and  brilliancy,  results  would  be  the 
same,  as  in  the  pear-shaped  sun  here  given. 

Period  of  revolution  around  mass  center,    13  days. 

Distance  between  centers  of  suns,  30,000,000  miles. 

Mass  of  small  sun,  greater  than  our  sun,  9  times. 

Mass  of  large  sun,  greater  than  our  sun,  18  times. 

Density  of  both  suns  is  less  than  that  of  air. 

Velocity  on  orbit,  no  miles  per  second. 

Distance  from  the  earth  unknown,  and  immeasurable! 

But  the  mass  is  known,  and  the  chief  work  of  human  hands 
wrought — mass  without  distance. 

The  mystery  is,  how  a  sun  of  such  low  density  can  be  hot 
enough  to  send  light  to  such  incredible  distances  as  the  earth. 
However,  electricity  may  be  in  activity  in  this  phase  of  matter. 
Such  intricate  problems  are  beset  with  chances  for  mistakes,  for 
if  errors  of  a  few  liundred-millionths  of  an  inch  are  made  in 
measuring  displacements  of  lines,  the  result  will  be  vitiated  by 
corresponding  errors. 

The  values  here  given  for  Beta  Lyne  are  those  of  Vogel,  de- 
termined with  his  new  spectrograph  lately  installed  in  Potsdam, 
as  shown  in  cut  102.  At  A  is  shown  the  end  of  the  great  visual 
telescope,  and  B  is  the  graphic  telescope,  for  waves  that  affect 
the  retina  of  the  eye  will  not  affect  silver  salts  to  make  good 
graphs.  So  the  objectives  have  different  focal  lengths.  At  I  is 
shown  the  case  inclosing  the  train  of  prisms.  These  analyze  faint 
stellar  light,  separate  the  waves  and  form  a  displacement  spec- 
trum on  the  sensitive  plate  at  2,  where  it  is  graphed  for  meas- 
urement of  its  lines  under  a  microscope. 

Cut  103  is  the  interior  of  the  spectrograph,  showing  three 
prisms  at  i,  and  the  plate  at  2.  At  3  is  an  opening  in  front  of  the 
slit  S,  where  may  be  placed  a  Geissler  hydrogen  tube,  flashed  by 
electricity,  so  that  its  light  can  enter  the  slit  with  that  from  the  star, 
for  comparison.  Since  the  lines  are  side  by  side,  either  from  a  reced- 


256 


RADIANT     ENERGY. 


ing  or  approaching  star,  with  those  from  the  incandescent  hydro- 
gen, lateral  shift  can  be  measured  with  accuracy  by  micrometer. 
Or,  if  iron  or  magnesium  are  prominent  in  the  star,  two  ter- 
minals of  these  metals  are  attached  to  the  poles  of  a  high  pressure 


Cut  103.     Interior  of  Dr.  Vogel's  Spectrograph. 

induction  coil,  and  are  flashed,  when  the  heat  turns  the  ends  of 
the  metals  to  incandescent  gas,  which  also  sends  vivid  light 
into  the  slit  for  measurement  alongside  of  the  same  metals  white 
hot  in  the  distant  stars. 

Dr.  Vogel  has  already  made  many  discoveries  in  the  motion 
of  stars  in  the  line  of  sight. 


RADIANT     ENERGY. 

POIvARIS. 

In  1899  Professor  W.  W.  Campbell  discovered  the  polar 
star  to  be  a  spectroscopic  binary  with  a  period  of  revolution  of 
3d.  23!!.  15111.  around  the  center  of  mass  of  itself  and  an  invisible 
companion.  But  this  center  of  gravity  was  found  to  be  itself  in 
motion  with  a  variable  velocity,  therefore  disturbed  by  a  third 
and  also  invisible  body.  Thus  two  suns  are  revolving,  and  a 
dark  world  like  the  earth  or  Mars  is  making  circuit  around 
them.  Hartman's  recent  researches  indicate  for  the  dark  planet 
a  period  of  fifteen  years,  and  Campbell  gives  its  speed  as  about 
two  miles  per  second,  at  a  distance  from  the  center  of  gravity  of 
the  two  suns  of  300,000,000  miles.  Computing,  the  combined 
mass  appears  to  be  closely  one-sixth  of  our  sun. 

CAPEI,I,A. 

This  magnificent  sun  was  discovered  to  be  a  spectroscopic 
biliary  by  Professor  Campbell  in  1899.  Its  periodic  time  of  revo- 
lution is  104  days,  with  a  speed  of  eighteen  miles  per  second ;  while 
its  mass,  according  to  Professor  Newcomb,  is  ten  times  greater 
than  that  of  our  sun.  Thus  a  majestic  and  new  branch  of  sideral 
astronomy  is  being  rapidly  developed.  New  and  improved  meth- 
ods of  computing  orbits  are  also  in  evolution,  notably  by  H. 
N.  Russel.  And  it  seems  likely  to  come  out  that  parallaxes  of 
stars  will  be  determined  with  accuracy  in  the  spectrograph  that 
are  so  far  away  that  the  telescope  alone  will  be  forever  unequal 
to  the  task. 

Doubtless  all  the  physically  connected  double  stars  aie  bina- 
ries, that  is  in  revolution  to  prevent  collapse  and  collision. 
Knowledge  of  the  universe  is  now  being  immensely  extended  in 
the  discovery  of  gigantic  suns  in  rapid  revolution  with  periods 
ranging  from  a  few  hours  to  many  years. 


258  RADIANT     ENERGY. 


XXXVI. 
STELLAR  EVOLUTION. 

"The  substance  of  the  heavens  and  of  the  stars  is  called  ether: 
not  that  it  is  composed  of  flame,  as  pretended  by  some  who  have  not 
considered  its  nature,  which  is  very  different  from  that  of  fire,  but  it 
is  so  called  because  it  has  an  eternal  circular  motion,  being  a  divine 
and  incorruptible  element,  altogether  different  from  the  other  four."— 
Aristotle,  "Letter  to  Alexander." 

"Amongst  the  stars  that  are  visible  move  others  that  are  invisible, 
to  which  in  consequence  we  are  unable  to  gives  any  names.  These  latter 
often  fall  to  the  earth  and  take  fire  like  that  star-stone  which  fell  all 
on  fire  near  /Egos  Potamos." — Diogenes  of  Apollonius. 

It  fell  to  the  lot  of  two  men  to  change  the  current  of  human 
thought  for  all  time.  Charles  Darwin  established  on  immova- 
ble rock  the  sublime  doctrine  of  evolution  among  living  things. 
And  his  not  less  illustrious  son,  George  H.  Darwin,  has  for  all 
coming  ages  rooted  and  grounded  the  profound  doctrine  of  evolu- 
tion in  all  inorganic  matter,  extending  to  the  confines  of  the 
sidereal  universe.  The  most  profound  and  abstruse  mathematics 
that  has  yet  evolved  in  the  human  brain  has  been  employed  in 
these  elaborate  researches.  This  gave  the  earth's  place — so  now 
the  evolution  of  all  animate  and  inanimate  things  can  be  traced. 
The  chief  product  of  intellect,  since  man  appeared,  is  primordial 
cosmical  evolution. 

The  brain  of  George  H.  Darwin  was  the  first  to  see 
that  the  surging  of  tides  in  ancient  liquid  or  gaseous  suns  did 


RADIANT     ENERGY.  259 

more  work  in  the  development  of  stellar  systems  than  any  other 
agency.  As  often  happens,  two  minds  on  earth  became  impressed 
with  a  great  truth  at  the  same  time.  Dr.  T.  J.  J.  See  saw  tfos 
basic  law  very  soon  after  Darwin,  as  an  independent  discovery, 
not  knowing  that  Darwin  had  also  seen  the  great  light.  The 
case  was  similar  to  that  of  Le  Verrier  and  Adams,  who  both 
computed  the  mass  of  Neptune  before  the  eye  of  man  had  looked 
upon  it.  For  mathematics  'has  clearer  vision  than  the  eye. 

D 


B 

Cut  104.     An  Ellipsoid. 

Cut  104  is  an  ellipsoid.  Suppose  a  gaseous  or  liquid  sun 
should  assume  this  form,  or  any  other  ellipsoidal  form  by  revolv- 
ing around  the  long  axis  AC  or  the  short,  DB,  then  will  the 
deviation  from  a  sphere  depend  on  its  speed  of  rotation  and  in- 
ternal viscosity.  Thus  the  earth  is  an  oblate  ellipsoid  revolving 
around  its  short  axis  DB.  Since  its  ellipticity  is  slight,  it  must 
have  been  in  its  consistency,  quite  viscid  when  its  crust  was 
formed. 

In  cut  105  let  two  spheroidal  suns  a  and  b  come  within  each 
other's  neighborhood  in  their  random  flight  in  early  stages  of 
evolution — for  all  suns  fly  at  random  now. 

Let  these  two  plastic  suns  pass  by  forever,  on  the  lines 
shown,  then  when  at  the  nearest  approach  their  gravity  will  act 
upon  each  other.  But  that  attraction  changes  their  entire  subse- 
quent career.  Let  one  or  both  suns  be  in  rotation  on  either  axis 
with  any  velocity.  Gravity  of  each  will  produce  distortion  on  the 
mobile  mass  of  the  other;  and  draw  it  out  of  the  regular  geo- 
metrical form.  But  centrifugal  tendency  of  rotation  still  acts 


260  RADIANT     ENERGY. 

on  the  changed  shape  and  produces  most  remarkable  and  far- 
reaching  results.  Each  mass  will  leave  its  original  path,  no  longer 
traverse  the  dotted  lines,  but  make  a  graceful  bow  or  nod  to  each 
and  recede  forever  on  a  hyperbola  for  a  track.  But  each  sun  will 
be  broken  into  two  suns.  Let  sun  b  evolute  itself,  and  direct  at- 
tention to  a,  where  it  is  seen  drawn  into  a  new  shape  by  the  at- 
tractions of  b,  as  shown  in  the  dotted  curve,  or  pear-shaped  mass. 
When  Darwin  and  See  were  casting  plumb  lines  over  the 


Cut  105.     Plastic  Suns  passing,  nearer  to  return. 

sidereal  structure,  the  French  geometer,  Poincare,  sunk  a 
sounding  line  into  the  fathomless  sea  of  space.  He  found  an 
equation  calling  for  an  entirely  new  geometrical  form  totally  un- 
known to  mathematicians,  and  of  course  not  known  to  La  Place 
when  he  formulated  his  famous  and  now  superseded  hypothesis 
of  the  formation  of  worlds  by  the  abandonment  of  peripheral  rings 
by  rotating  and  subsiding  gaseous  or  liquid  masses. 

Cut  1 06  is  Poincare's  all-important  apioid,  through  which 
form  many  binary  suns  are  now  known  to  be  passing.  The  apioid 
is  based  on  rigorous  mathematical  formulas,  which  he  elaborated. 

LAW :  Where  there  is  a  mathematical,  there  is  also  a  physi- 
cal possibility. 


RADIANT     ENERGY. 


261 


Could  the  brain  of  that  great  mathematician,  La  Place,  now 
become  reanimate,  its  genius  would  doubtless  at  once  give  up 
mainly  the  ring  doctrine  of  stellar  evolution.  It  is  possible  that 
a  nebula  may  break  up  into  rings  by  action  of  other  masses  and  its 
own  tenuity  and  internal  state,  but  that  is  not  the  leading  fact  in 
nature. 


Cut  106.     Poincare's  Apioid. 


GEMMATION. 


Here  is  encountered  a  mighty  law  that  seemingly  holds  the 
whole  of  nature  in  its  grasp,  reaching  from  a  minute  living  amoeba 
to  white-hot  sun.  In  cut  107  is  shown  the  process  of  gemma- 
tion of  an  apoid  sun  to  form  two.  Figure  I  is  the  regular 


Cut  107.     An  Apioid  Sun  dividing  into  two. 


geometric  apioid  rotating  in  the  direction  of  the  arrows.  In  figure 
2  contraction  is  more  pronounced,  while  in  figure  3  the  segmenta- 
tion is  well  advanced,  and  the  wondrous  work  is  complete  in 
4,  when  two  suns  are  formed,  both  rotating  in  the  same  direction 
of  the  original  cosmical  mass.  Each  sun  may  be  gaseous  or  liquid 


262 


RADIANT     ENERGY. 


and  from  one  million  to  a  thousand  million  miles  in  diameter,  ac- 
cording to  their  constitution,  whether  liquid  or  gas.  This  is  a 
phase  of  evolution  of  inanimate  matter.  But  all  living  matter 
makes  identical  evolution. 


Cut  108.    An  Amoeba  making  Segmentation. 

Cut  1 08  is  that  of  one  amoeba  making  reproduction  by  gem- 
mation, and  all  animals,  from  amoeba  through  all  protozoans,  ra- 
diates, mollusks,  articulates  and  vertebrates  to  man,  are  simply 
congeries  of  cells. 


Cut    109.     The  Sun  V  Puppis  in  Process  of  Gemmation. 
The  ligament  is  about  to  be  severed. 

The  binary  sun  named  V  Puppis,  from  a  discussion  of  all  ob- 
servations by  A.  W.  Roberts,  will  satisfy  equations  based  on  spec- 
troscopic  determinations,  by  the  mathematical  figure  in  cut  109, 
where  light  still  lingers  in  the  band  not  yet  torn  asunder  in  the 
forming  suns.  These  giant  suns  make  revolution  in  one  day  ten 
hours  and  fifty-four  minutes,  and  their  density  is  only  one-fifth 
that  of  our  sun. 


RADIANT     HN  HRGY.  263 


XXXVII. 
EVOLUTION  WROUGHT  BY  TIDES. 

"The  lovely  Dawn,  arousing  man,  goes  before  the  sun  preparing 
practicable  paths,  riding  in  a  spacious  chariot;  expanding  everywhere  she 
diffuses  light  at  the  commencement  of  the  day." 

"Harnessing  the  purple  oxen  to  her  car,  unwearied  she  renders 
riches  perpetual;  a  goddess  praised  of  many,  and  cherished  by  all,  she 
shines  manifesting  paths  that  lead  to  good." — Rig  Veda  Sanhita,  Vol. 
HI,  p.  369- 

The  computation  of  the  action  of  primeval  tides  on  form- 
ing worlds  and  suns  involved  a  grade  of  mathematics  much  more 
complex  than  the  formulas  employed  in  the  discovery  of  the  loca- 
tion and  mass  of  Neptune  before  the  eye  of  man  had  seen  it. 
George  H.  Darwin  first  gave  tidal  formulas  to  the  scientific  world 
and  aroused  the  supreme  admiration  of  all  who  heard  the  won- 
drous story. 

PRIMEVAL  TIDES. 

Darwin's  mathematics  looked  on  primeval  chaos,  where  lens 
and  plate  are  useless.  He  began  his  history  of  evolution  with 
the  ancient  earth  and  its  moon,  but  the  reasoning  applies  to  the 
development  of  binary  suns  as  well.  Tides  began  the  next  day 
after  the  moon  separated  by  gemmation  from  the  equator  of  the 
earth ;  neither  had  time  to  assume  the  spherical  form  before  tidal 
force  clutched  both.  Tides  formed  the  earth  and  moon. 


264.  RADIANT     ENERGY. 

FIRST  DAY. 

The  first  day  began  at  the  instant  the  umbilical  cord  leading 
from  the  viscous  earth  to  her  daughter  the  moon  was  severed, 
and  ended  when  the  point  of  rupture  came  round  to  the  same  place 
again.  The  first  month  began  at  the  instant  of  the  moon's  birth 
and  ended  when  it  also  came  to  the  same  point  after  one  circuit 
around  the  primitive  earth.  Both  day  and  month  have  from  that 
time  been  in  constant  change  in  length ;  they  are  both  changing 
now — no  two  of  either  being  precisely  of  the  same  duration.  The 
first  day  and  first  month  were  very  nearly  equal,  and  the  length 
of  each  somewhere  between  three  and  five  hours.  Not  exactly 
equal,  for  then  there  would  not  have  been  tidal  friction — the 
worker  that  made  both  day  and  month — for  the  same  face  of  the 
moon  would  have  forever  been  turned  toward  the  earth  and  the 
same  point  on  the  earth  toward  the  moon.  There  would  have  been 
one  high  tide  on  the  earth  under  the  moon,  and  on  the  moon  op- 
posite, but  no  friction,  so  both  worlds  would  be  held  by  gravity, 
as  if  joined  by  a  rigid  rod  of  steel,  and  hence  no  friction,  and  both 
month  and  day  would  have  remained  between  the  mathematical 
limits  of  three  and  five  hours.  The  difference,  no  matter  how 
slight,  between  the  early  months  and  early  days  was  no  doubt 
caused  by  the  disturbance  of  rupture,  but  if  any  variation  what- 
ever occurred,  then  tidal  friction  formed  the  earth-moon  system 
as  it  now  exists. 

FRICTION  DUE  TO  TIDES. 

A  tide  in  water  is  known  to  have  friction  within  its  mass.  A 
tide  in  oil,  tar,  honey,  liquid  steel  or  melted  rocks  would  cause  far 
more  internal  friction  than  tides  in  water,  alcohol  or  gasoline.  The 
action  of  tidal  friction  is  as  universal  as  the  law  of  gravity,  heat 
or  electricity,  and  its  discovery  and  mathematical  development 
takes  rank  with  the  discovery  of  gravity  and  its  Newtonian  law. 
The  reader  is  referred  to  XXXVI  for  cuts  showing  the  ancient 
apioidal  earth  and  the  separation  of  the  moon  mass. 


RADIANT    ENERGY.  265 

HOW   TIDES  PLACED   THE   MOON   ON   ITS   PRESENT   ORBIT. 

The  mechanics  of  tides  and  tidal  friction  may  be  seen  in  cut 
no,  adapted  to  the  purposes  of  this  note  from  both  Dr.  See  and 
Professor  G.  H.  Darwin,  omitting  all  technical  and  mathematical 
portions. 

Figure  a  shows  a  circle  and  an  ellipse,  or  a  sphere  and  an 
ellipsoid.  The  sphere  represents  the  form  of  the  earth  if  sunk  in 
space  far  away  from  any  attracting  body;  really  the  earth  has 
never  been  a  true  sphere.  The  ellipsoid  represents  the  shape  of 
the  semi-liquid  or  plastic  earth,  with  tides  at  T  and  t,  caused  by 


CUT  110 — Showing  the  mechanics  of 
tides  arid  trtial  friction. 


the  moon  at  m.  If  the  day  and  month  had  been  at  that  time  equal 
in  length,  the  tides  would  always  have  remained  as  at  T  and  t  on  a 
straight  line  with  the  centers  of  the  earth  and  moon,  until  it 
cooled  and  a  solid  crust  formed,  so  the  earth  would  now  be  an  el- 
lipsoid. If  the  day  and  month  were  of  unequal  length,  and  the 
substance  of  the  earth  absolutely  without  friction,  then  the  centers 
of  the  earth  and  tides  would  have  been  on  the  same  right  line; 
but  this  is  impossible,  for  even  hydrogen  has  friction  within. 

EFFECT  OF  FRICTION. 

But  the  early  days  were  shorter  than  the  month,  and  the 
viscidity  of  the  earth's  mass  had  more  friction  than  a  water  world. 
The  effect  was  most  important  and  is  now  known  to  be  at  least 
one  riddle  of  the  universe. 


266  RADIANT     HN  HRGY. 

Let  figure  a  represent  noon  of  the  first  day,  or  morning,  or 
evening,  and  figure  b  the  same  time  on  the  next  day.  But  the 
day  was  shorter  than  the  month — that  is,  the  earth  rotated  on  its 
axis  faster  than  the  moon  revolved  in  its  orbit.  This  would  have 
no  effect  in  the  absence  of  internal  friction,  but  friction  was  pres- 
ent, the  tide  wave  was  retarded,  could  not  keep  straight  below  the 
moon,  so  the  more  rapid  earth  carried  it  by  the  line  joining  the 
centers  of  the  earth  and  moon,  as  shown  by  cut  no,  figure  b, 
where  the  dotted  line  T,  t,  is  the  axis  of  the  tide  next  day,  and 
has  been  from  that  archaic  time  and  must  ever  be  until  the  earth 
becomes  throughout  more  rigid  than  steel,  and  the  oceans  solid 
ice.  In  figure  b  the  moon  is  around  to  m  again  at  the  end  of  the 
month,  but  tide  T  is  always  in  advance  of  the  place  it  would  have 
been  had  friction  failed,  and  is  now. 

MECHANICS  OF  TIDES.     ACTION  EQUAL  TO  REACTION. 

Tide  T  is  nearer  the  moon  than  t,  hence  the  attraction  of  the 
moon  on  T  is  stronger  than  on  t.  The  pull  of  the  moon  on  the 
gravity  rope  on  T  tends  to  pull  back  T,  to  bring  the  doted  line 
T-t  into  its  original  line  m-c,  while  the  weaker  attraction,  m-t, 
tends  to  counteract  it  and  make  the  earth  turn  faster,  but  m-T  is 
the  strongest  and  must  prevail.  So  the  earth  is  actually  slowing 
down  its  rotary  speed  now,  the  day  is  growing  longer,  and  even 
during  all  that  time  since  the  first  day. 

The  mass  in  tide  T  reacts  and  pulls  on  the  moon  and  tends 
all  the  time  to  make  it  go  faster  on  its  orbit  in  the  direction  of 
the  arrows.  The  pull  t-m  tends  to  retard  the  moon,  but  T-m  is 
more  potent,  it  acts  with  greater  intensity  on  the  moon  and  tends 
to  increase  its  speed  and,  therefore,  make  the  month  shorter.  One 
on  first  reading  would  think,  of  course,  that  the  month  was  in 
these  early  times  growing  shorter,  but  such  evidently  was  not  the 
case,  for  it  is  twenty-seven  and  one-third  days  long  now,  and  less 
than  five  hours  in  length  then. 


RADIANT     BNBRGY.  267 

The  instant  the  moon  is  accelerated  a  mighty  reaction  — cen- 
trifugal tendency — lays  hold  upon  it.  This  terrific  power  is  not 
an  inherent  property  of  matter,  but  merely  a  reaction  against 
original  inertia  common  to  matter  in  every  form. 

Tie  a  cord  to  a  stone,  whirl  it  around,  the  string  pulls ;  double 
the  velocity  and  the  pull  increases  four  times,  that  is,  this  reaction 
is  enormous — it  varies  as  the  square  of  the  velocity,  as  observed 
in  bursting  grindstones.  A  solid  wheel  of  steel  will  fly  to  pieces  if 
turned  fast  enough. 

As  soon  therefore  as  the  chaotic  moon  was  accelerated  cen- 
trifugal tendency  threw  it  away  farther  from  the  earth  into  a 
longer  orbit.  It  required  more  time  to  make  a  revolution.  Thus, 
incredible  as  it  may  seem,  tidal  friction  pushed  the  moon  away 
from  the  earth  and  made  the  month  longer.  The  united  chaotic 
earth  and  moon  revolved  on  an  axis  before  the  moon  made  escape 
by  segmentation,  so  the  term  "first  day"  above  means  the  first  time 
the  earth  made  one  rotation  separate  from  the  moon.  Had  it  not 
rotated  before,  then  a  furrow  or  fissure  would  not  have  formed 
owing  to  absence  of  centrifugal  tendency  in  the  apioidal  mass. 
Not  only  the  past  of  the  earth  and  moon  can  be  traced,  but  the 
future.  The  revelations  made  by  Darwin  are  more  astounding 
than  any  ever  presented. 


268 


RADIANT     ENERGY. 


GEORGE    H.    DARWIN 


RADIANT     ENERGY.  269 


XXXVIII. 
EVOLUTION  OF  THE  EARTH  AND  MOON. 

The  sun  remains  immovable,  and  the  earth  moves  round  it  in  a  circular 
curve,  of  which  that  star  is  a  center. — Aristarchus  of  Samos. 

THE:  FIRST  MONTH. 

Given  a  difference  between  the  length  of  the  first  day  and 
first  month,  however  slight,  even  to  a  minute  fraction  of  a  second, 
then  the  present  state  of  the  earth  and  moon  was  inevitable.  The 
entire  mechanical  work  has  been  wrought  by  mutual  tides.  The 
agency — heat — has  been  escaping  since,  and  the  less  the  heat  in 
both  earth  and  moon  the  thicker  the  consistency  of  both  masses, 
the  lower  the  tides  in  both  on  account  of  increased  friction,  and  the 
less  the  distance  the  moon  must  recede  before  it  turns  and  begins 
its  long  period  of  winding  on  a  spiral  back  to  the  earth.  This 
question  of  how  tides  forced  the  moon  away  from  the  earth  must 
be  understood,  for  it  is  a  fundamental  law  in  nature.  Tidal  fric- 
tion has  done  more  work  than  all  other  agencies  combined  in  the 
formation  of  planetary  systems — where  worlds  revolve  around 
suns.  It  is  the  giant  now  at  work  building  up  binary,  ternary  and 
multiple  suns,  at  present  seen  in  active  evolution  in  every  direc- 
tion in  space.  In  fact,  it  is  the  great  worker  of  the  universe, 
being  the  only  method  by  which  the  primal  power,  gravity,  can 
get  worlds  in  its  clutch  to  hurl  them  upon  orbits.  It  separates 


270  RADIANT     ENERGY. 

matter  in  the  shape  of  crude  chaotic  masses,  so  the  heat  of  the 
central  mass  shall  not  be  too  intense  to  destroy  life  on  later  re- 
volving planets.  Tides  made  our  earth  and  moon.  Friction  due 
to  tides  completely  accounts  for  the  evolution  of  the  sidereal  uni- 
verse. The  vast  subject  must  be  understood  by  all  who  wish  to 
know  about  the  immense  cosmical  structure  so  overwhelming  in 
its  majesty  and  splendor.  A  book  is  required  to  treat  this  great 
new  deduction  of  the  human  mind ;  so  only  elementary  principles 
will  be  presumed  upon  here,  not  even  daring  to  go  near  where 
Darwin  is  but  once,  and  that  to  touch  the  "hem  of  his  garment." 
This  is  the  absolute  beginning  of  evolution  of  moons  in  place 
around  planets,  planets  and  moons  around  suns,  suns  and  planets 
around  other  suns,  and  underlies  the  substructure  of  all  stellar 
systems.  If  acceleration  is  understood  the  outlines  of  that  stu- 
pendous machine,  the  universe,  will  be  seen  emerging  from  the 
most  archaic  obscurity  like  the  coming  of  a  ship  from  the  mists 
of  the  sea. 


a.  6- 

CUT     112. 

Composition  of  two  forces  into  one. 
The  forces  ac  and  ab  are  united  into  ad, 
all  moving  \n  direction  of  the  arrow?. 


ACCELERATION. 


The  mystery  of  acceleration  is  cleared  in  cut  112,  which 
shows  first,  the  basic  law  of  mechanics,  the  composition  of 
forces.  Let  a  mass  be  at  a,  and  at  rest.  Let  a  force  act  upon  it  in 
the  direction  a,  c,  with  an  impulse  able  to  cause  it  to  move  from 
a  to  c  in  one  second.  At  precisely  the  same  instant  let  another 
force  act  upon  a  with  an  intensity  able  to  send  it  to  b  in  two 
seconds.  It  will  not  move  either  to  c  or  b,  but  will  arrive  at  d. 


RADIANT     ENERGY. 

The  path  a,  d  is  always  the  diagonal  of  a  parallelogram,  if  the 
forces  are  unequal ;  of  a  square  if  equal.  Any  number  of  simulta- 
neous forces  can  be  compounded  into  one.  This  law  had  to  do 
with  the  evolution  of  all  solar  systems.  The  composition  of  forces 
— gravity  and  friction — on  the  primordial  moon,  reveals  the  hid- 
den mystery  why  it  left  the  earth. 


Cut  113.     Tides  separating  the  Earth  and  Moon. 

In  cut  113,  e  is  the  ancient  viscid  earth,  and  m  the  chaotic 
moon,  both  in  the  grasp  of  gravity  and  in  the  clutch  of  tides. 
In  cut  no,  chapter  XXXVII,  the  moon  is  shown  acting 
on  the  earth,  and  in  cut  113  the  earth  is  acting  on  the  moon;  they 
shall  be  compared.  In  cut  113  e  is  the  ellipsoidal  earth  drawn 
away  from  the  dotted  circle  by  the  moon.  The  tide  at  v  accel- 
erates the  moon  on  its  orbit  ab  towards  b.  If,  when  the  moon 
arrived  at  m,  the  earth  were  suddenly  annihilated  the  moon 
would  move  on  the  tangent  to  its  orbit,  t.  If  the  mass  of  the 
earth  as  suddenly  increased,  the  moon  would  move  toward  v.  If 
no  change  occurs,  the  moon  will  keep  on  its  orbit  to  b.  But  the 
heaping  up  of  matter  at  v  has  somewhat  the  effect  of  increasing 
the  quantity  of  matter  in  the  earth,  because  it  brings  some  of  it 
nearer  to  the  moon  and  thrusts  other  portions  away,  as  at  x,  that 
of  v  pulling  with  greater  force  on  the  line  v  m  than  if  v  were  sunk 
within  the  dotted  circle  below.  But  at  the  instant  the  speed  of 
the  moon  is  increased,  the  mighty  centrifugal  tendency  asserts  its 
sway  and  hurls  it  off  the  orbit  ab  and  sets  the  moon  upon  its  new 
track  ao,  farther  away  from  the  earth.  And  this  is  why  the  moon 


2J2  RADIANT     ENERGY. 

is  240,000  miles  away  from  the  earth  instead  of  almost  in  con- 
tact, and  why  the  length  of  the  month  is  27  1-3  days  instead  of 
scarcely  more  than  one.  The  only  reason  why  high  tides  developed 
at  v  and  x,  was  because  of  friction  in  the  viscous  earth ;  for  with- 
out friction  tide  v  would  have  been  exactly  under  the  moon,  and 
tide  x  opposite,  the  day  and  month  being  always  equal  and  the 
surfaces  of  the  moon  and  earth  almost  coinciding. 

At  the  end  of  the  first  month,  if  it  was  any  longer  than  the 
first  day  by  any  time  whatever,  and  if  the  earth's  mass  had  friction 
by  any  amount  however  minute,  then  the  present  earth  and  moon, 
and  the  present  day  and  month  were  inevitable.  For  at  the  end  of 
the  first  month  the  moon  is  again  at  m,  but  still  farther  from  the 
earth  and  will  traverse  an  orbit  slightly  outside  of  ao,  and  so  on 
for  each  month,  perpetually  expanding  its  orbit  like  unwinding 
a  closely  wound  coil  or  flat  disc  of  tape.  It  will  continue  to  un- 
wind so  long  as  tides  exist,  either  on  the  surface  or  within  the 
earth,  the  longest  month  being  when  the  last  tide  on  earth  shall 
die  away  into  rigidity.  It  will  be  noticed  that  at  the  moon's  orbit 
each  new  path  described  at  the  beginning  of  every  new  month  is 
the  diagonal  of  a  new  parallelogram,  as  in  cuts  112  and  113. 
FUTURE  OF  THE  EARTH  AND  MOON. 

It  is  shown  in  the  history  of  tidal  evolution  that  if  the  first 
month  had  been  shorter  than  the  first  day,  the  moon  must  have 
fallen  back  on  the  earth  after  the  rupture  of  the  ligament,  if,  in- 
deed, such  disruption  could  have  taken  place  by  the  action  of  the 
earth  and  moon  without  the  aid  of  the  tides  caused  by  the  sun. 
However,  the  first  month  was  longer  than  the  first  day,  else  the 
earth  would  not  have  a  moon  now.  These  results  must  follow : 
The  length  of  the  first  day  and  month  was  somewhere  between 
three  and  five  hours;  mathematics  could  compute  the  true  time  if 
accurate  data  could  be  had  in  chaotic  states  of  the  earth-moon. 
I  kit  it  is  a  stupendous  achievement  to  know  that  it  falls  within  set 
limits.  If  either  three,  four  or  five  hours,  the  truth  of  the  doc- 


RADIANT    ENERGY.  273 

trine  of  tidal  evolution  is  not  effected.  The  month  is  now  27  1-3 
times  longer  than  the  day.  But  friction  of  tides  has  increased,  is 
now  increasing,  and  will  continue  to  lengthen  both  day  and  month 
until  they  become  equal,  at  which  time  each  will  be  fifty-five  of  our 
present  days  in  length.  It  will  take  the  earth  fifty-five  times 
longer  to  make  one  turn  on  its  axis  than  now,  and  the  moon  very 
nearly  twice  as  long  to  make  one  circuit  around  the  earth  than 
at  present.  They  will  then  be  as  firmly  fixed  in  relation  to  each 
other  as  though  joined  to  the  ends  of  a  bar  of  steel.  If,  when  so 
clutched  as  in  the  jaws  of  a  mighty  vise,  the  moon  is  central  over 
the  United  States  there  it  will  remain.  The  moon  is  clutched  by 
the  earth  now,  and  always  presents  the  same  face  this  way.  It  is 
only  a  question  of  time  when  the  earth  will  obey  the  moon's 
gravity  and  turn  the  same  face  to  it.  They  will  still  revolve 
around  their  center  of  mass,  as  may  be  seen  by  attaching  two 
unequal  balls  to  a  rod,  suspending  by  a  cord  at  their  gravity  center 
and  turning.  The  earth  and  moon  will  still  revolve  around  the 
sun,  and  the  earth  will  have  271/2  times  longer  day  than  now  and 
night  also,  if  the  sun  is  shining  then,  if  not,  one  perpetual  night 
with  moon  invisible.  But  in  all  probability  the  sun  will  be  dead. 
Thus  when  lunar  evolution  began  the  day  and  month  differed, 
necessarily,  by  only  a  fraction  of  a  second,  and  when  evolution 
ends  the  day  and  month  will  again  be  equal — the  first  day  being 
between  three  and  five  hours  long  and  the  last  1,320  hours  (fifty- 
five  days).  The  greatest  number  of  days  in  a  month  was  twenty- 
nine,  and,  as  there  are  now  27  1-3,  evolution  is  slightly  more  than 
half  through  with  its  career.  Therefore,  the  least  number  of  days 
in  a  month,  the  first  and  last,  is  one;  the  greatest  twenty-nine. 
Matters  are  different  on  our  neighbor  Mars,  for  its  satellite  Phobos 
counts  off  more  than  three  months  every  day  of  Mars ;  rises  in  the 
west,  passes  through  all  its  phases  in  plain  view  of  the  Martians, 
each  phase  being  less  than  two  hours  in  duration.  The  sum  and 
substance  of  the  evolution  of  moon  and  planet  from  primitive 


274.  RADIANT    ENERGY. 

apioidal  shape  is  that  the  first  month  of  the  detached  moon  shall 
be,  any  time  whatever,  longer  than  the  first  day.  The  same  is 
true  of  binary  suns.  For  if  the  month  is  longer  than  the  day  all 
parts  of  the  earth  pass  in  review  before  the  moon,  if  not  there 
would  be  no  tides.  And  tides  would  be  useless  in  absence  of  in- 
ternal friction.  So  the  cause  of  evolution  of  moons  and  planets 
and  of  binary  suns  is 

TIDAL  FRICTION. 

Darwin's  rigid  analysis  surely  points  to  the  fact  that  the 
final  state  of  the  earth  and  moon  will  be  one  of  stable  equilibrium. 
No  fact  in  nature  is  better  authenticated.  The  first  state  was  un- 
stable, else  the  earth  would  not  have  a  satellite  now.  The  sole 
cause  of  unstability  was  friction  in  tides.  In  the  terminal  state 
there  will  be  no  tides,  for  the  earth  will  be  as  solid  as  the  moon  is 
at  present.  The  earth  and  moon  will  be  in  deadlock  and  escape 
impossible.  The  term  "last  day"  above  is  the  day  on  which  the 
sun  sends  its  last  wave  of  light  to  the  earth  and  moon.  Both  will 
still  revolve  around  their  center  of  gravity  in  a  period  now  called 
fifty-five  days,  in  night  that  knows  no  dawn.  Long  before  this 
all  life  will  vanish  from  earth,  but  if  Byron's  last  man  could  be 
on  the  equator,  his  only  method  of  finding  if  the  earth  turned 
would  be  to  watch  the  stars — younger  than  our  star — the  sun.  To 
him  the  moon  would  be  unknown  as  well  as  the  sun. 

The  revolution  will  continue,  the  earth  and  moon  still  casting 
lifeless  periods  of  time  into  past  duration,  while  both  will  revolve 
on  melancholy  pathways  around  a  frigid  sun,  recording  useless 
times  called  years.  Matter  in  which  life  is  able  to  exist  separates 
with  exceeding  ease  and  terminates  the  fleeting  pulsation.  The 
seething  unrest,  the  heat,  the  clashing,  kneading  and  rushing  tur- 
bulence of  the  gigantic  masses  of  suns  and  worlds  in  the  midst 
of  evolution  must  be  hushed  for  a  few  moments  into  almost  ab- 
solute quiescense  and  repose  that  life  might  appear  and  vanish, 
Thus  life  is  a  mere  episode  in  the  process  of  evolution  of  nature. 


RADIANT    ENERGY. 


275 


XXXIX. 

EVOLUTION   NOW  IN   ACTIVITY. 

"That  which  is  one  the  wise  call  many  ways.    They  call  it  Indra,  Mitra, 
Varuna,  Agni,  the  winged  heavenly  Garutmat." — Rig  Veda  I,  164,  46. 

Stellar  evolution  has  by  no  means  ceased,  it  is  in  an  active 
state  now,  and  can  be  watched  by  means  of  the  telespectroscope  in 
all  directions  in  space.  Gemmation  of  one  sun  into  two,  allows 
tides  to  set  in  and  furnish  suns  and  worlds  with  moons.  At  the 
instant  of  separation  of  two  worlds,  tides  must  act  and  build  both 
into  suns.  Gravity  is  inherent  in  all  matter,  but  cannot  build  a 
universe  unless  it  exerts  its  power  by  the  leverage  of  tides  and 
these  cannot  build  without  friction.  Since  friction  is  also  inherent, 
gravity  and  tidal  friction  formed  and  fashioned  all  that  portion 
of  the  sidereal  edifice  within  range  of  the  best  telespectro-cam- 
eras,  for  these  write  the  history  of  cosmic  evolution  hour  by  hour. 
Cosmical  life  and  death  seem  to  be  equal.  Suns  ending  evolution, 
so  far  as  can  be  learned  at  present,  are  comparable  in  number 
to  those  entering  their  long  career.  The  quantity  of  matter  now 
stored  in  dead  worlds  is  greater  than  that  in  the  hot  and  living. 

The  waste  products,  as  far  as  science  in  its  present  condition 
is  able  to  see,  »are  heat  and  a  minute  trace  of  energy  called  light. 
Both  are  episodes  and  momentary  while  gravity  is  as  eternal  as 
matter.  Heat,  light  and  life  are  ephemeral,  while  matter  and 
gravity  are  constant.  All  else  in  the  universe  at  present  known 
to  men  is  variable.  Gravity  is  the  builder  and  has  wrought  in  the 


276  RADIANT    ENERGY. 

past  and  is  now  acting  through  friction.  Centrifugal  tendency  is 
a  reaction  merely  against  gravity.  Gemmation  prepares  the  way 
for  its  instant  successors,  gravity  and  its  opposing  entity.  These 
two,  and  time,  formed  all  worlds.  Thus  activity  is  derived  from 
gravity. 

Matter  and  gravity  existed  before  the  universe  assumed  its 
present  structural  form,  while  astronomy  and  cosmical  physics 
both  teach  that  they  will  exist  if  it  ends.  If  the  fashioned  struc- 
ture does  not  end,  that  is,  revert  to  chaos,  then  evolution  is  eternal. 
Tt  has,  however,  been  decided  by  psychologists,  that  the  word 
eternal  is  powerless  to  make  impress  on  the  human  mind,  so 
vagaries  about  duration  must  give  way  to  what  is  known. 

MOTIONS  OF  THE  STARS. 

The  words  "fixed  stars"  have  now  disappeared  from  the  lit- 
erature of  modern  astrophysics.  It  is  known  that  every  star  is  in 
rapid  motion.  They  move  in  every  possible  direction  and  the  fact 
stands  out  that  they  move  at  random  like  bees  in  a  swarm.  It 
is  almost  impossible  that  any  should  move  on  straight  lines.  A 
right  line  is  almost  unknown  in  nature.  The  distances  between 
suns  are  so  enormous,  that  gravity  is  weak  from  sun  to  sun,  so 
the  curvature  of  solar  orbits  is  slight.  If  the  stellar  structure 
is  finite,  it  has  a  center  of  mass,  and  all  suns  and  worlds  whether 
alive  or  dead,  must  obey  its  attraction  in  a  measure;  yet  a  hun- 
dred suns  in  the  vicinity  of  our  sun  might  temporarily  attract 
it  more,  than  the  immensely  distant  gravity  center  of  all  the  suns. 
Since  whether  the  universe  is  finite  or  infinite  is  unknowable,  the 
center  of  universal  attraction  may  be  ignored,  and  attention  paid 
to  adjacent  suns.  Since  they  all  move,  the  effect  on  every  other 
is  variable,  so  every  sun  in  existence  moves  with  varying  velocity 
on  a  curve  which  is  perpetually  changing  its  curvature  and  direc- 
tion. 


RADIANT    ENERGY.  277 

Cut  114  represents  a  finite  portion  cut  out  of  an  infinite  sys- 
tem of  stars,  with  motions  in  every  direction. 


Cut  114.    Any  number  of  Suns  cut  out  of  any  space. 
They  move  in  every  direction. 

Cut  115  represents  the  observed  and  measured  movements 
of  the  stars  in  the  Great  Dipper  in  the  constellation  Ursse  Major, 
where  five  suns  are  seen  moving  in  the  same  direction,  all 
presumably  condensed  from  the  same  nebula,  while  one  af  the 
pointers  and  one  in  the  handle  are  in  motion  in  other  directions. 
These  motions  were  measured  by  micrometer,  but  the  spectro- 


Cut  115.     Drift  of  Stars  in  the  Great  Dipper. 

scope  shows  that  the  five  suns  are  in  rapid  motion  away  from 
the  earth,  while  the  pointer  (A)  is  approaching  and  the  star  (E) 
receding  with  a  speed  different  from  that  of  the  five  common  suns. 
All  but  eight  of  the  stars  of  that  well-known  group,  the 
Pleiades  (cut  116),  move  in  one  direction,  so  all  these  glittering 
suns  are  supposed  to  have  been  condensed  from  one  mass  of  gas. 
It  is  also  known  that  our  sun  is  moving  with  great  velocity 
through  lonesome  space,  dragging  its  worlds  along  with  perfect 


278  RADIANT    ENERGY. 

order.  Thus  binary,  ternary  and  multiple  suns,  as  well  as  single 
stars  like  ours,  and  also  groups,  all  have  their  own  motions  ;  bin- 
aries, of  course,  and  related  groups  having  the  same  direction,  in 
relation  to  each  other,  but  every  conceivable  direction  in  relation 


Cut  116.     Drift  of  Pleiades. 


to  space  and  all  the  other  stars.  So  there  are  no  fixed  or  motion- 
less suns  in  space.  Indeed,  there  could  not  be  bodies  at  rest  in 
free  space  dominated  by  the  ruler  of  all  —  Gravity. 


RADIANT    ENERGY.  279 


WIDE  DIFFUSION  OF  MATTER. 

"Nature,  beginning  of  ages,  is  parent  of  all." — Diodorus  1-27.  Apu- 
leitis,  Metamorphoses. 

The  writer  has  seen  incandescent  hydrogen  glowing  in  the 
stars  Vega  and  Sirius.  Sirius  sets  when  Vega  rises,  therefore  they 
are  in  opposite  directions  from  the  earth.  The  distance  between 
these  two  giant  suns  is  256  trillion  miles,  and  they  are  in  our  im- 
mediate neighborhood,  for  other  stars  known  to  contain  hydrogen 
are  as  much  as  one  hundred  times  farther  apart.  The  mighty 
question  at  once  arises,  how  came  hydrogen  so  widely  distributed 
in  interminable  space  ?  It  is  omnipresent,  and  seems  to  enter  the 
most  archaic  nebulae  and  thence  condense  into  suns.  But  it  is 
too  dense  to  fill  all  that  portion  of  space  now  known  to  be  occu- 
pied by  suns  and  cool  worlds.  Iron  is  conspicuous  and  also  mag- 
nesium, together  with  helium,  in  the  most  primitive  type  of  suns. 

When  suns  become  older  and  more  complex  other  modes  are 
seen  in  the  spectroscope.  The  only  possible  explanation  of  the 
fact  that  iron  and  hydrogen  are  seen  glowing  in  suns  in  every  di- 
rection, whose  distance  apart  are  many  quadrillion  miles,  is  that 
all  matter  now  stored  in  suns  and  worlds  was  once  separated  into 
an  exceedingly  rare  gas,  or  rather  ultra  gaseous  form.  For  any 
gas  known  to  chemists  here,  under  terrestrial  conditions,  is  many 


28o  RADIANT    ENERGY. 

hundred  million  times  too  dense  to  be  compared  with  the  probable 
diffusion  of  primordial  matter.  Helium  and  hydrogen  particles 
would  be  miles  apart  if  all  matter  now  existing  in 
suns  appearing  on  late  graphic  plates  should  be  uni- 
formly distributed.  And  these  are  the  rarest  modes 
known.  But  the  discovery  of  J.  J.  Thomson  of  corpuscles 
that  have  only  one-thousandth  of  the  mass  of  the  hydrogen 
particle  throws  much  light  on  the  primeval  chaotic  mass, 
whence  all  suns  and  worlds  were  developed  by  processes  of  evolu- 
tion, now  observed  in  activity  in  every  direction  in  space.  These 
corpuscles  have  awakened  the  interest  of  every  physicist  in  the 
world,  and  they  are  either  electricity  itself  or  its  immediate  car- 
riers. A  great  fact  seems  to  be  prefigured — the  universe  is  based 
in  electricity,  for  electricity,  no  doubt,  is  a  mode  of  matter. 

At  all  events,  speculate  as  one  will,  it  is  certain  that  if  all 
matter  now  condensed  into  suns  visible  in  the  most  powerful  tele- 
camera  were  expanded  into  the  same  space  now  occupied  by  them, 
then  space  would  not  be  filled,  for  even  these  corpuscles  would  be 
separated  by  distances  very  large  compared  to  their  diameters. 

Let  all  that  part  of  space  at  present  occupied  by  suns  and 
worlds  in  every  possible  phase  of  evolution  be  occupied  by  mat- 
ter dissipated  into  an  excessively  rare  condition,  so  rare  that  the 
Thomsonian  corpuscles  were  inches  or  even  feet  apart — then  the 
development  of  the  original  mass  into  a  universe  such  as  now  ex- 
ists was  sure  to  follow  from  known  physical  laws. 

EVOLUTION   OF  SUNS. 

In  cut  117,  let  the  circle  cut  out  space  in  diameter  the  distance 
traversed  by  light,  moving  with  a  speed  of  186,000  miles  per  sec- 
ond during  30,000  years.  This  is  not  extravagant,  for  Sir  Robert 
Ball,  Astronomer  Royal,  estimates  that  the  faintest  stars  of  the  sev- 
enteenth magnitude  are  so  distant  that  18,000  years  are  required 


RADIANT    ENERGY.  281 

for  light  to  reach  the  earth,  making  the  diameter  of  the  cosmic 
structure  visible  to  man  36,000  light  years.  To  be  within  bounds, 
30,000  years  is  the  period  selected  for  computation  in  this  note. 
The  circle  is  drawn  merely  to  attract  the  eye,  and  has  no  other 
use. 

Kelvin  has  shown  that  the  number  of  particles  of  any  gas  in 
one  cubic  inch  cannot  exceed  six  sextillion.  The  size  of  Thom- 
son's corpuscles  is  unknown,  their  mass  only  being  determined, 
which  is  the  one-thousandth  that  of  the  hydrogen  particle.  Doubt- 
less, however,  their  diameter  is  in  some  equivalent  ratio,  so  the 


Cut  117.    Cosmical  Sphere  of  Suns,  30,000  light  years  in  diameter. 

number  above  becomes  one  thousand  times  greater,  or  six  septil- 
lion.  In  the  appalling  space  selected,  each  corpuscle  had  plenty  of 
room.  The  temperature  was  absolute  zero — 273  degrees  C,  and 
solid  hydrogen  and  air  would  be  warm  in  comparison. 

Absolute  rest  at  first  obtained,  when  the  sole  ruler  of  mat- 
ter— gravity — asserted  sway,  and  motion  began.  If  two  corpus- 
cles united,  that  was  the  beginning  of  a  nebula,  of  which  many 
thousands  are  now  seen  in  all  parts  of  the  sidereal  structure  in 
every  conceivable  shape,  faint  wisps  and  filmy  forms  of  original 
gas  born  of  condensation  from  primordial  corpuscular  matter. 

After  inconceivable  eons  passed  away,  the  appearance  of 
things  within  the  circle,  so  far  as  science  can  at  present  find,  was 


282 


RADIANT    ENERGY. 


like  that  in  cut  118,  where  nebulae  have  formed  in  all  parts  of  the 
sphere,  starting  from  minute  corpuscular  nuclei.  It  is  the  destiny 
of  every  nebula  to  condense  into  suns,  for  the  process  can  now 
be  seen  and  photographed  on  every  clear  night.  These  countless 
nebulae  are  at  present  seen  on  the  plates  in  every  possible  phase 
of  evolution  from  the  faintest  and  most  diffused  mass  of  rare  gas 


Cut  118.     Nebulae  and  Suns  in  evolution. 


up  to  the  final  or  solar  stage.  In  cut  118,  amoeba  form  nebulae  are 
shown;  and  also  those  in  the  shape  of  spirals,  for  Keeler's  graphs 
revealed  many  to  have  the  spiral  form.  Probably  these  were  in 
rotation. 

All  nebulae  so  far  subjected  to  spectrum  analysis  show  hy- 
drogen, others  present  helium,  and  many  have  lines  emanating 
from  a  mode  of  matter  not  yet  detected  on  the  earth,  provisionally 
named  nebulium. 


D'    7  311  If 

\  III    I 


Cut  119.    Spectrum  of  a  bright  Nebula.    Iyines  3,  4  and  5  are  due  to  hydrogen  and  C 

is  from  helium.      Lines  1,  2  and  7  are  from  an  unknown  mode,  but  called 

nebulium;  5  and  7  are  faint  and  invisible  in  dim  nebulae. 

Cut  119  is  the  spectrum  of  nebulae,  only  the  brightest  being 
able,  in  a  powerful  spectrograph,  to  show  all  of  the  seven  lines. 


RADIANT    ENERGY.  283 

The  line  6  is  due  to  helium,  which  was  unknown  for  a  long  time, 
always  being  seen  in  the  sun  as  well  as  in  nebulae.  It  was  dis- 
covered by  Ramsay  on  the  earth  in  1895,  and  isolated,  when  its 
line  was  found  to  coincide  with  the  line  in  both  sun  and  nebulae. 
Thus  helium  and  hydrogen  hover  round  about  the  beginning  of 
evolution  of  the  universe. 

Astronomy  and  astrophysics,  in  their  present  state,  are  un- 
able to  see  any  other  possible  method  of  sidereal  evolution  than 
that  here  given.  For,  if  all  existing  suns  were  evolved  in  the  vicin- 
ity of  the  center  of  the  circle,  the  problem  comes  up — how  did 
they  become  dispersed  to  such  incredible  and  inconceivable  dis- 
tances in  which  they  are  now  seen  ?  Separation,  due  to  Darwin's 
tides,  seems  to  be  impossible,  for  gravity  becomes  very  weak  at 
these  enormous  distances. 

In  fact,  the  standing  mystery  of  all  astronomy  is  space.  Why 
should  suns  now  be  separated  by  such  unfathomable  space  ?  Why 
should  our  nearest  neighbor  be  25  trillion  miles  away  ?  For  it  can 
be  shown  that  if  Alpha  Centauri  were  only  one  trillion  miles  dis- 
tant our  planetary  system  would  not  be  perturbed  by  any  measur- 
able quantity. 

Evolution  extends  from  corpuscle  to  dead  suns  and  frigid 
worlds.  In  the  turbulence  and  turmoil  heat  was  the  first  mode  of 
radiance  to  appear,  then  light ;  moisture  came,  and  then  life. 

But  life  is  of  exceedingly  short  duration.  The  evanescent, 
fleeting,  unstable  and  feeble  thing  or  entity — life — was  the  last 
to  appear  in  the  midst  of  the  stupendous  cosmic  war  of  matter  and 
energy,  and  will  be  the  first  to  vanish.  A  few  degrees  change  in 
temperature  either  way  will  end  it  all.  Short  as  may  be  the  dura- 
tion of  organic  life,  that  of  its  chief  product — mind — is  shorter 
still.  For  life  existed  ages  on  the  earth  before  its  last  refine- 
ment, coherent  thought,  was  evolved.  Thus  mind  has  the  least 
duration  of  any  entity  whatever,  for  soon  mentality  will  vanish, 
unconsciousness  set  in  and  oblivion  succeed. 


284.  RADIANT    ENERGY. 

It  can  be  shown  that  if  the  sidereal  structure  is  in  rotation 
about  an  axis,  the  centrifugal  tendency  is  unable  to  project  out- 
lying suns  to  their  present  distance,  so  the  conclusion  is  inevitable 
that  all  space  now  occupied  by  suns  must  have  been  filled  with  ma- 
terial whence  they  were  made  by  gravity  and  tides.  If  so,  then  the 
tenuity  of  the  mass  was  so  great  as  to  reach  the  ultimate  or  final 
corpuscular  state. 

If,  as  seems  probable  in  the  present  state  of  ignorance,  cor- 
puscles are  electricity,  then  electricity  is  the  first  and  last  refine- 
ment of  matter,  for  the  indications  of  astrophysics  are  that  the 
sidereal  structure  must  be  resolved  back  to  the  corpuscular  state 
again  to  recondense  into  another.  This  mutation  is  necessary 
to  regain  heat,  which  at  present  is  being  lost  at  a  frightful  rate. 

And  modern  science  here  has  arrived  at  the  same  conclusion 
reached  by  our  primeval  Aryan  ancestors  at  the  base  of  the  Hindu 
Kuh,  in  Northern  India,  many  thousand  years  ago.  For  that 
recondite  Hindu  philosophical  poem,  the  "Bhagavad  Gita,"  says: 
"Matter  is  invisible  in  its  primordial  state,  visible  in  its  inter- 
mediate, and  invisible  in  its  final  state."  The  latest  science  has 
nothing  better  to  offer.  Helium  and  hydrogen  are  the  perpetual 
enigma.  Why  should  the  first  matter  to  send  out  light  be  these? 
And  how  is  it  that  iron  appears  so  early  upon  the  cosmic  scene 
of  upheaval,  unrest  and  activity,  or  why  should  matter  assume 
the  eighty  phases  now  known?  Or  what  is  matter?  Perhaps 
these  old  questions  never  will  be  solved  by  man,  yet  the  astound- 
ing discoveries  of  the  last  two  years  appear  to  indicate  that  they 
may  not  be  beyond  human  powers. 

Cut  1 20  is  that  of  the  great  spiral  nebula  in  Canes  Venatici. 
Several  suns  are  shown  that  have  been  condensed  from  the  vast 
mass  of  gas.  To  the  right,  a  large  body  of  gas  is  separating  by  the 
gemmation  process,  while  the  whole  presents  the  outlines  of  a  gi- 
gantic spiral.  Thus  the  history  of  cosmical  evolution  has  been 
given  as  far  as  science  can  see  at  present.  Whether  the  entire 


RADIANT    ENERGY. 


285 


Cut  120.    Spiral  Nebula.     Canes  Venatici. 

congeries  of  suns  and  worlds  revert  back  to  the  corpuscular  state 
at  the  same  time,  or  whether,  while  some  are  dissolving  to  chaos, 
others  far  away  are  just  emerging  from  it,  are  questions  at  pres- 
ent insoluble.  The  new  sun  in  Perseus  last  year  was  seen  to  re- 
solve into  a  chaotic  nebula.  Mystery  deepens,  while  men  pale  and 
faint  in  presence  of  these  mighty  problems. 


2S6  RADIANT    ENERGY. 


XLL 

PRIMORDIAL  ELECTRICAL  INDUCTION. 

"Thou  art  the  arts  and  sciences,  thou  moral  and  political  wisdom. 
The  worlds  have  been  preserved  and  reanimated  by  thee." — Indra's  Praise 
of  Lakshima.  From  Vishnu  Purana  I,  Ch.  ix. 

Induction  is  a  deep-seated  fact  in  nature.  In  this  paper  elec- 
trical induction  will  be  employed  in  striving  to  account  for 
the  archaic  mystery  of  rotation.  Very  many  theories  have  been 
advanced  to  account  for  the  rotation  of  primitive  nebulae,  as  well 
as  spherical  gaseous  suns,  and  liquid,  round  about  axes.  How  did 
rotary  motion  begin,  and  what  mode  of  energy  caused  these  vast 
masses  to  turn?  In  cut  118,  Paper  XL,  the  primal  gaseous  sphere 
is  seen  broken  into  great  numbers  of  nebulae,  and  some  are  rep- 
resented as  having  passed  their  successive  steps  of  evolution  up 
to  complete  suns.  But  all  worlds  in  our  solar  system,  as  well 
as  the  central  sun,  are  in  rapid  rotation  on  axes.  And  from  phe- 
nomena of  variable  stars  it  is  inferred  that  all  suns,  planets  and 
satellites  are  turning. 

The  writer  believes  that  this  universal  motion  of  rotation  was 
caused  by  electrical  induction.  The  phenomena  of  inductance 
ought  to  be  understood  by  all,  for  nearly  all  electrical  machines, 
now  rapidly  coming  to  the  front  as  the  workers  of  the  world,  are 
based  on  the  fact  that  electricity  acts  at  a  distance  and  induces 
other  mechanism  to  do  work. 


RADIANT    ENERGY.  287 

This  is  cleared  in  cut  121,  where  A.  B  and  C  are  spheres — 
those  so  often  used  by  the  writer  before  students — being  wooden 
croquet  balls  covered  with  a  coating  of  lead  or  tinfoil.  The  balls 
were  all  suspended  by  a  silk,  or  non-conducting,  thread  to  the  ceil- 
ing of  the  laboratory.  The  ball  A  is  to  be  charged  by  the  in- 
duction of  C.  The  sphere  C  is  to  be  provided  with  a  charge  of 
electricity  from  an  electrophorus,  Helmholtz,  Atkinson,  or  any 
static  machine,  in  another  part  of  the  room,  and  carried  to  its 
position  of  suspension.  Suppose  the  coating  is  charged  positively 
as  shown.  It  instantly,  by  induction,  separates  the  natural  elec- 
tricity, with  which  all  known  matter  is  endowed  in  the  sphere  A, 


CUT  121— Charging  the  sphere,  a,  with 
electricity  by  induction  exerted  by  the 
electricity  in  the  sohere,  b. 

the  negative  moving  to  the  side  nearest  C,  by  reason  of  C's  attrac- 
tion, while  the  positive  is  repelled  to  the  opposite  side,  as  may 
be  seen  by  the  signs  plus  and  minus. 

For  unlike  attracts  and  like  repels.  Separation  is  one  of  the 
chief  mysteries  of  nature,  and  always  precedes  attraction.  The 
ball  C  must  not  be  allowed  to  touch  A  under  any  circumstances, 
for  then  A  would  be  charged  by  conduction — not  induction.  At 
this  point,  gradually  bring  B  to  the  position  shown.  Lightning 
will  dash  across  the  space  between  with  a  snapping  sound.  The 
positive  on  A  flies  to  B,  and  soon  as  this  occurs  the  sphere  B  must 
be  removed,  and  C  also,  leaving  A  alone  in  the  air. 

Now,  since  man  began  to  handle  electricity  nothing  more 
wonderful  than  this  has  been  seen  by  mortal  eye,  nor  ought  that 
seems  to  approach  nearer  the  confines  of  nature  than  the  strange 
property  now  possessed  by  the  sphere  A. 


288  RADIANT    ENERGY . 

LAW — Electricity  on  its  surface  has  power  to  attract  and 
cause  motion  in  every  mode  of  matter. 

This  activity  is  shown  in  cut  122,  where  a  and  d  are  suspended 
as  before,  while  e  is  a  hydrogen  toy  balloon  attached  to  a  peg 
below.  By  reason  of  the  experiment,  a  was  charged  negatively; 
but  by  the  same  method  it  might  have  been  endowed  with  positive, 
in  either  case  it  will  attract  any  substance  known.  This  is  shown 
in  the  mass  d,  which  has  been  tried  with  wood,  stone,  glass,  metal, 


CUT  122— The  charge  sphere,  a,  .at- 
tracting and  causing  motion  in  any  known 
mode  of  matter,  d,  and  also  in  a  hydrogen 
balloon,  e. 

tallow,  paraffine,  oil,  rubber,  paper  and  other  substances,  and  they 
all  move  toward  a  as  shown  by  dotted  outlines.  Gases  are  also  at- 
tracted as  in  the  case  of  the  hydrogen  in  e.  If  the  shape  of  d  is 
unsymmetrical  with  regard  to  its  center  of  mass  it  will  also  rotate 
on  an  axis.  If  a  is  moved  around  d  in  a  circle  d  will  rotate  at  the 
same  rate,  following  every  motion  of  a.  Let  a  be  removed  to  a 
distant  part  of  the  room.  Then  d  will  still  continue  to  turn  until 
brought  to  a  rest  by  friction  of  air  and  torsion  of  the  thread. 

LAW — The  mass  d  in  a  vacuum  would  rotate  forever. 

And  the  hypothesis  of  archaic  induction  is  advanced  here  with 
the  hope  that  obscure  cosmological  problems  may  be  cleared.  In 
cut  123,  the  principles  of  inductance,  separation  and  attraction 
wrought  by  static  electricity  are  transferred  from  the  physical 
laboratory  to  the  primitive  and  formative  cosmical  masses  after 
they  had  advanced  from  the  original  corpuscular  state  to  widely 
separated  and  slightly  condensed  nebulae.  Let  the  nebula 


RADIANT    ENERGY.  289 

a  be  negatively  charged  as  in  cut  121.  Lightning  is  seen  escaping 
in  a  positive  charge  to  the  nebula  at  the  left.  Then  let  nebula 
a,  carrying  its  wonderful  power  of  attraction,  in  addition  to  its 
inherent  gravity,  wander  among  its  neighbors  at  random.  Let 
it  pass  b  in  the  lower  portion  of  the  sphere.  It  will  separate  the 
electricity  in  b  and  the  total  negative  quantity  in  a  will  attract  the 
positive  and  repel  the  negative  in  b,  forming  a  mechanical  couple, 
and  cause  b  to  rotate  in  the  direction  of  the  arrow. 


[  Cut  123.     The  Negatively  charged  Nebula  A,  is  supposedjo  cause  rotation 
in  B  by  Electrical  Attraction. 

For  there  is  no  more  reason  to  doubt  that  electricity  was 
present  in  vast  quantities  in  the  primitive  nebulae  than  to  doubt 
that  it  is  in  intense  activity  in  terrestrial  clouds  of  vapor.  In 
early  stages  of  evolution  before  suns  appeared  the  most  appalling 
lightnings  flashed  from  nebulae  to  nebulae,  whose  dimensions  in 
many  cases  then,  as  are  plainly  seen  now,  were  hundreds — yea, 
thousands  of  times  larger  than  that  vast  nebula  whence  our  own 
sun  was  formed. 

What  mighty  import  hovers  round  the  word  evolution.  For 
giant  modes  of  energy  wrought  and  struggled  in  war.  Matter 
was  shaken,  oscillated,  kneaded,  boiled  and  tumbled  in  the  throes 
of  chaos.  Phantom  forms  of  nebulae  were  clutched  in  awful 


290  RADIANT    ENERGY. 

churning,  in  seething  whirlpools,  and  throbbed  with  energy.  Ab- 
solute zero  and  darkness  reigned,  useless  indeed;  cold  light  can 
be  in  the  most  frigid  space. 

And  silence  reigned  save  from  lightning,  in  the  twisting 
gaseous  masses,  for  friction  had  scarcely  set  in.  The 
hosts  of  nebulae  were  not  yet  in  the  relentless  grasp  of 
the  Darwinian  tides.  But  when  pent  up  electricity  burst  all 
bounds  with  the  concussion  as  of  a  hundred  worlds  of 
broken  glass,  primordial  thunders  rolled — without  ear  to  hear.  As 
soon,  therefore,  as  electricity  was  separated  by  induction,  one  por- 
tion escaped  by  flashing  to  another ;  then  that  nebula  had  potency 
and  power  to  move  through  space  and  set  up  rotation  in  all  other 
nebulae  adjacent  to  its  erratic  pathway.  And  some  other  oppositely 
induced  mass  would  also  cause  it  to  make  rotation. 

It  is  known  from  mechanics  that  whatever  movement  of  rota- 
tion was  impressed  upon  a  nebula  by  another  passing  it,  must  be 
retained  forever  if  space  is  vacuous.  Here  is  the  great  law  of 
conservation  of  areas: 

LAW. — When  a  system  of  particles,  in  rotation,  changes 
form  or  size,  the  sum  of  all  the  areas  described  by  each,  in  any 
unit  of  time,  is  constant. 

This  is  one  corner  stone  of  that  edifice,  the  visible  universe. 
A  particle  in  making  one  circuit  around  the  center  describes 
a  circle  which  has  its  own  definite  area.  Now  let  the 
diameter  of  the  rotating  mass  shrink  to  one-half,  and 
if  it  still  remains  a  sphere,  the  area  of  the  circle  cut  out  by 
the  particle  in  its  new  position  will  be  only  one-fourth.  Then  it 
must  rotate  four  times  faster  to  cut  out  four  circles  which  together 
will  have  the  same  area  as  the  large  one.  The  motion  is  called 
areolar  velocity.  Therefore,  the  earth  now  has  the  same  quantity 
of  rotary  motion  that  was  imparted  it  when  a  rare  nebula  by 
ihe  gravity  and  inductance  of  some  other  nebula  that  passed  it 
in  primordial  times,  less  than  consumed  by  tides. 


RADIANT    ENERGY.  291 

QUANTITY   OF    MATTER. 

In  cut  124  let  the  sphere  be  such  that  light,  having  a  known 
speed  of  186,000  miles  per  second,  requires  30,000  years  to  trav- 
erse its  diameter.  Imagine  the  sphere  to  contain  500,- 
000,000  suns,  each  containing  the  same  quantity  of  matter  now 
stored  in  our  sun,  and  let  them  be  uniformly  distributed  as  shown. 
Consider  a  to  be  a  stone  or  sun  falling  from  infinite  space^ 
that  is,  it  has  fallen  forever.  Of  course,  the  two  words  infinite 
and  forever  make  no  impress  of  their  true  meaning  on  such  weak 
minds  as  those  now  possessed  by  man.  For  man  is  ignorant  con- 
cerning duration  and  space.  It  can  be  shown  by  rigid  mathe- 


Cut  124.      Sphere  of  Suns  and  Dark  Bodies,  whose  diameter  is  such  that  light 
moving  186,000  miles  per  second,  requires  30,000  years  to  traverse. 

matics,  and  has  been  by  Newcomb  and  others,  that  the  final  ve- 
locity on  arriving  at  the  center  of  mass  of  the  sphere  of  suns 
would  be  twenty-five  miles  per  second.  But  the  sun  1,830  Groom- 
bridge  is  now  seen  to  be  flying  with  the  terrific  velocity  of  200 
miles  per  second,  at  least.  For  Newcomb  does  not  give  its  paral- 
lax in  his  late  work,  "The  Stars,"  showing  it  to  be  so  far  away 
that  astronomers  are  unable  to  measure  its  distance.  Its  velocity 
is  beyond  doubt  more  than  200  miles  per  second.  This  leads  to 
the  most  remarkable  conclusion  regarding  the  quantity  of  matter 
within  the  30,000  light  year  circle  or  sphere. 

ACTIVITY  AND  VELOCITY. 

From  dynamical  laws  it  is  known  that  it  requires  four  times 
the  force  to  double  the  speed  of  a  falling  body.  Thus  doubling 
the  motion  to  fifty  miles  per  second  requires  four  times  the  num- 


292  RADIANT    ENERGY. 

ber  of  suns,  or  two  billion.  Doubling  again  the  speed  is  100  miles, 
with  eight  billion  suns.  With  double  this,  or  the  terminal  velocity, 
of  200  miles  per  second,  the  number  of  suns  required 
is  thirty-two  billion,  each  one  being  as  massive  as  our  sun.  The 
graphic  plates  with  long  exposure,  even  to  the  faintest  magnitudes 
able  to  make  impressions,  show  less  than  125,000,000  and  more 
than  100,000,000  suns.  Admitting  that  each  contains  as  much 
matter  as  the  sun,  then  only  one  in  320  emits  light  strong  enough 
to  impress  the  most  sensitive  plates.  But  our  sun  contains  suffi- 
cient quantity  of  the  matter  to  make  333,000  worlds  of  the  size 
and  density  of  the  earth.  Then  333,000  multiplied  by  thirty-two 
billions  equals  the  mass  of  eleven  quadrillion  bodies  like  the  earth 
attracting  the  flying  star.  The  visible  sidereal  structure  is  of  in- 
conceivable antiquity  and  is  far  more  massive  than  thought  pos- 
sible. 

Blackened  death  has  encountered  most  all  the  suns ;  only  one 
in  320  is  now  emitting  life-giving  heat  and  light,  or  being  pres- 
ent to  throw  feeble  and  fitful  gleams  on  their  funereal  paths. 
Another  star  is  now  known  to  be  moving  faster  than  1830  Gr., 
making  the  visible  and  invisible  universe  still  more  massive. 


RADIANT    ENERGY. 


293 


SUMMARY. 

The  latest  deductions  of  science  are  that  evolution  set  its 
mighty  clutch  on  all  existing  matter  when  it  was  in  an  excessively 
rare  ultra-gaseous  or  corpuscular  state,  filling  all  space  now  oc- 
cupied by  suns.  Gravity  was  the  only  mode  of  energy,  and  the 
first  to  act. 

Nuclei  formed  and  these  attracted  adjacent  corpuscles  form- 
ing countless  nebulae.  These  still  contracted  and  grew  more  dense. 
Electricity  appeared  and  began  the  work  of  building  a  universe, 
of  rotating  suns  by  induction.  Heat  and  light  came  later  on  the 
primordial  cosmical  scene  of  turmoil,  save  that  momentarily  ap- 
pearing at  times  of  the  outbursts  of  electricity.  The  heat  and 
light  evolved  by  contracting  suns  came  far  later,  as  well  as  from 
chemism.  Gemmation  wrought  also  in  nebulse  as  well  as  in  gas- 
eous and  liquid  suns,  separating  one  into  two.  And  the  process 
of  division  continued  in  planets  and  their  moons.  Soon  as  gem- 
mation finished  its  work  producing  any  two  suns,  then  that 
mighty  and  chief  builder,  the  tides,  laid  hold  on  the  primeval 
masses  and  fashioned  both  into  suns  and  worlds  revolving  in  reg- 
ular orbits  around  their  centers  of  mass.  Through  contraction, 
heat  developed  and  light  on  small  worlds  after  nearly  all  the 
heat  had  vanished,  water  came,  and  coarse  life,  then  more  re- 
fined, and  lastly  mind,  along  toward  the  close  of  evolution.  It 
contemplates  the  stupendous  scene  a  few  seconds  and  disappears. 
Each  mind  gains  one  or  two  impressions  of  the  objects  on  display 
and  dies.  Were  it  not  for  the  custom  of  recording  these  fitful 


294.  RADIANT    ENERGY. 

thoughts  and  ideas,  in  print,  in  sculpture,  on  obelisk  and  walls, 
on  bricks  and  cylinders,  and  now  by  that  marvelous  process — 
making  records  on  graphic  plates — ignorance  would  reign  su- 
preme, for  it  is  only  by  storing  minute  fragments  of  knowledge 
gained  by  each,  that  a  fund  can  be  accumulated. 

Coherent  thought  in  modern  times  began  in  1610,  so  it  is  but 
300  momentary  years  since  wisdom  began  to  be  stored.  For 
the  awful  and  withering  poison  of  the  dark  ages  subverted  mind. 
The  three  centuries  have  produced  the  lens,  the  calculus,  the  grat- 
ing and  the  graphic  plate,  four  engines  with  which  men  are  now 
hourly  wresting  new  and  long  delayed  secrets  from  nature.  Be- 
ginning evolution  in  corpuscular  conditions,  the  universe  of  mat- 
ter passes  all  stages  of  youth,  adolescence,  maturity  and  death, 
the  death  consisting  of  loss  of  heat.  Then  if  the  titanic  founda- 
tions are  torn  up  and  billions  of  dead  suns  and  frigid  worlds  are 
hurled  together  with  the  most  appalling  speed  so  that  heat  enough 
due  to  collision  and  friction  will  be  developed,  to  dissipate  all  back 
to  corpuscles  again,  refilling  the  same  space,  the  total  mutation 
will  have  constituted  one  sidereal  universe  and  made  all  things 
ready  for  another.  Thus  one  phase  of  matter  will  have  been 
passed  the  whole  constituting  one  wave  as  shown  in  cut  125. 


Cut  125.     One  Wave. 


THE   END. 


ADDENDA. 


The  Lowe  Observatory.* 

The  location  of  this  observatory  is  unique  in  many  respects. 
It  stands  on  a  peak  whose  apex  was  cut  off  abruptly  to  secure 
a  flat  surface  for  the  building.  This  central  summit  is  in  a  vast 
amphitheatre,  formed  of  colossal  peaks  round  about,  some  on  a 
level  with  the  observatory  and  others  1200  feet  above.  On  either 
side  are  yawning  canyons.  Rubio  on  the  east,  670  feet  deep, 
descends  precipitously  from  the  walls  of  the  observatory;  while 
Los  Flores'  Gorge  makes  rapid  descent  to  a  depth  of  1250  feet 
on  the  west.  A  chain  of  old  Sierra  Madre's  range  is  bent  and 
coiled  in  mighty  links  enclosing  both  canyons,  the  central,  or 
Echo  Mountain,  and  observatory  peak,  and  extends  from  the 
southeast  round  through  the  east  and  north,  through  northwest, 
and  rapidly  declines  to  the  west,  where  the  range  dwindles  into 
the  Verdugo  hills  overlooking  that  paradise  of  oranges,  apri- 
cots and  grapes,  the  famous  La  Canada  Valley.  Still  beyond 
and  nearer  the  sea,  eight  rows  of  hills,  ranging  from  north  to 
south,  are  visible.  These  are  the  Tejunga  hills  and  Simi  and 
Santa  Monica  ranges  of  low  mountains.  Speech  is  impotent  to 
portray  the  glories  of  the  sunsets  from  the  vernal  equinox  to  the 
summer  solstice  and  return  to  the  equinox  of  autumn.  The 
angles  made  by  these  ranges  with  the  ecliptic,  are  such  that  the 
declining  sun  pours  its  radiant  floods  between,  lighting  up  the 

*From  the  Bret  Harte  Memorial  Number  of  the  OVKRLAND  MONTHLY,  Sept.,  1902. 


298  LOWE     OBSERVATORY. 

gloomy  and  solitary  canyons  with  supernal  colors.  For  dust1 
from  waste  places  on  the  hills,  and  from  Mojave's  desert  areas, 
comes  in  contact  with  watery  molecules  thrust  over  by  the  break- 
ers of  the  Pacific  in  their  dashings  against  Simi's  granite  bul- 
warks, and  these  absorb  and  quench  some  of  the  waves  of  light, 
allowing  others  to  illuminate  summits,  valleys,  canyons  and 
domes  with  hues  and  tints,  all  blending  into  one  stupendous 
panorama  of  surpassing  loveliness  and  beauty.  So  remarkable 
is  this  scene  that  iron  railings  are  placed  on  the  canyon's  edge, 
for  travelers  from  all  parts  of  the  earth,  who  come  to  behold 
the  sun  as  it  sinks  into  the  sea.  It  is  Sunset  Point,  Los  Flores 
Canyon.  But  it  is  to  the  mighty  and  serrated  contour  of  cliffs 
and  peaks  that  scientific  interest  is  attached.  So  transparent  is 
the  air  that  minute  stars  are  seen  at  the  absolute  instant  of  rising. 
Thus  the  writer  never  saw  a  star  at  the  moment  of  its  advent 
above  the  horizon,  until  coming  to  this  enchanted  place.  Not 
sorcerer  of  Egypt  or  Eleusis  ever  conjured  up  a  more  magnifi- 
cent spectacle,  or  weird  influence,  nor  impression  more  fasci- 
nating to  mind  and  sense,  than  the  marvelous  display  of  rising 
celestial  bodies.  The  great  nebula  in  Orion  issues  out  of  a 
smooth  wind  and  sand-worn  rock,  and  so  clear  is  the  air  that  five 
stars  in  the  trapezium  have  been  seen  standing  on  stone,  while 
the  light  of  the  great  nebula  suffers  but  little  diminution.  Since 
the  telescope  reverses  all  objects,  rising  stars  seem  to  be  going 
downward  toward  the  earth,  and  language  cannot  describe  the 
wonders  of  the  rising — falling — Pleiades,  for  this  glittering  host 
of  1300  stars,  as  seen  in  the  L,owre  telescope,  seem  to  be  pouring 
into  old  Rubio's  cavernous  depth.  And  the  unutterable  glories 
of  the  Galaxy — how  see  them  in  a  lifetime  or  how  recount  their 
splendors — for  illimitable  hosts  of  stars  pour  in  floods  into  the 
chasm  and  this  Niagara  of  stellar  diamonds,  rubies  and  sapphires, 
flows  with  stately  motion  into  the  insatiable  recesses  below.  The 
edge  of  Saturn's  ring  cuts  its  way  up  and  out  of  a  rocky  cliff, 


LOWE    OBSERVATORY.  299 

and  Jupiter  at  times  sends  up  a  tiny  moon  before  it  appears; 
but  last  night  it  escaped  from  a  tangle  of  manzanita  bushes  far 
on  the  mountain's  height.  The  star  Castor  is  seen  double  be- 
tween the  leaves  and  branches  of  a  shrub,  while  the  nebula  of 
Andromeda  is  always  enmeshed  in  a  wilderness  of  low-growing 
chaparral.  Altogether  this  clear-cut  mountain  horizon  is  so 
beautiful  that  description  fails  and  words  lose  their  power. 

THE  SIDEREAL  STRUCTURE  WITHOUT  THE  TELE- 
SCOPE. 

Many  more  stars  can  be  seen  here  without  optical  aid  than 
from  low  plains.  The  observatory  is  above  more  than  half  of 
the  dust  layer  that  encloses  the  entire  earth  as  an  envelope.  It 
is  no  trouble  to  see  the  sixth  magnitude  stars.  The  stars  burn 
and  blaze  with  a  brilliancy  unknown  to  observers  below. 
Sagitarius  and  Scorpio  hang  up  their  sidereal  sheets  like  a 
drapery  of  cloth  of  pearl  over  the  waves  of  the  Pacific.  The 
Milky  Way  is  whiter  than  as  seen  from  observatories  in  Illinois 
and  the  East,  and  the  sky  blacker.  The  colors  of  the  stars  are 
on  display  with  greatly  increased  splendor,  and  contrast  is  more 
pronounced  than  elsewhere.  But  all  glories  pale  and  faint  be- 
fore that  awful  and  sublime  object  as  seen  in  the  Lowe  telescope. 

THE  STELLAR  FLOOR. 

The  majestic  pavement  of  the  universe  is  surely  visible  from 
this  observatory.  It  is  the  background  or  foundation  of  the 
sidereal  structure.  It  is  either  made  up  of  countless  millions  of 
inconceivably  distant  stars,  or  a  solid  external  envelope  of  nebu- 
lous matter.  It  is  beyond  the  Milky  Way,  and  wider.  It  is 
not  visible  in  all  parts  of  the  sky,  but  areas  far  removed  from 
the  Galaxy  are  filled  with  it.  The  general  structure  of  nature 
is  surrounded  or  clothed  with  a  fabric  of  pearl ;  but  the  delicate 
texture  is  rent  and  torn  in  thousands  of  places.  The  appalling 


joo  LOWE    OBSERVATORY. 

blackness  of  space  appears  in  these  ragged  openings.  Cosmical 
rifts,  cracks  and  seams  are  seen  here  in  great  numbers.  Special 
observation  has  been  made  of  Scorpio  and  Sagitarius.  Over 
one  hundred  rents  and  jagged  openings  in  the  white  stellar  floor 
have  been  seen  in  these  two  constellations.  Some  are  clear-cut 
and  small,  others  large,  diffuse,  with  torn  and  twisted  edges,  and 
these  are  not  jet  black  within.  A  film  seems  to  be  stretched  in 
front.  It  is  doubtful  if  the  white  floor  is  entirely  absent  even 
at  the  Galactic  poles.  When  taking  charge  of  this  observatory, 
the  first  thought  was  a  mistake  had  been  made  concerning  the 
winding  sheet  of  the  visible  universe;  so  nothing  was  published 
for  one  year,  to  test  the  seeing  in  all  kinds  of  weather  and  con- 
ditions of  air.  It  was  surmised  that  the  white  shimmer  and 
sheen  in  the  distant  background  of  the  cosmical  sphere,  was  due 
to  the  well-known  action  of  dust  causing  diffusion  of  light  in  the 
earth's  atmosphere.  Many  tests  were  made  on  this  point,  with 
the  result  that  the  cosmic  floor  was  seen  in  certain  localities,  on 
the  same  nights,  when  black  space  was  seen  between  stars  in 
adjacent  and  also  in  distant  regions.  So  it  is  said  that  the  pri- 
mordial substructure  of  the  universe  is  on  display  here.  It  is 
doubtful  if  long  time  graphs  will  show  this  pavement  as  well  as 
the  eye,  for  the  stars  in  the  foreground  will  store  their  light  in  ex- 
cess in  front  of  the  distant  wall.  If  the  azoic  rocks  of  stars  or 
nebulae  really  exists  below  and  beyond  all,  then  the  sidereal  edifice 
is  far  more  magnificent  and  larger  than  hitherto  thought  possible. 
That  is,  that  portion  of  the  structure  visible  in  telescopes,  or  on 
plates,  is  merely  cut  out  of  an  original  universal  nebula. 

STARLESS    FIELDS. 

If  the  stellar  pavement  is  impressive,  what  shall  be  said  of 
those  caverns  in  which  no  star  is  seen,  nor  any  nebulous  gleam  of 
light.  After  looking  for  a  long  time  at  the  multitude  of  stars, 
finer  than  any  sand,  or  as  fine  as  the  granules  of  silver  bromide 


LOWE     OBSERVATORY.  3oi 

on  graphic  plates,  the  telescope  sweeps  into  view  a  space  black  as 
ink,  the  effect  on  the  mind  is  always  startling.  It  is  difficult 
to  account  for  these  openings  in  the  structure  of  stars,  for  there 
must  be  long,  empty  tubular  spaces  extending  from  the  place  of 
the  earth,  even  to  the  floor  of  stars.  At  all  events,  they  are  black. 
Here  long  exposure  of  sensitive  plates  might  store  light  enough 
to  make  visible  impress,  and  long-time  graphs  should  be  made 
of  central  portions  of  the  blackest  starless  areas.  Here  is  a  list 
of  several  spaces  in  the  starry  pavement: 

PHOSPHORESCING  AREAS  OF  THE  COSMICAL 

FLOOR. 

Right  ascensions.  Declinations. 

H.  M.  Degrees.       Minutes. 

3  20 

2  50 

2  30 

23  55 

22  OO 

21  45 

21  00 

Next  to  the  last  in  the  table  is  notable,  for  the  floor  and  a  star- 
less area  are  seen  in  the  same  field  of  view,  both  distinct.  The 
edges  of  the  pavement  are  smooth,  like  the  rim  of  a  well  cut  in 
stone,  while  the  second  in  the  catalogue  has  rough  and  distorted 
boundaries  of  stars  round  about  the  cavern. 

STARLESS  FIELDS.    APPROXIMATE  CENTERS. 

16  50         S  22  20  l8  10        S  20 

17  25      S  26        35        18        10     S  18        25 

18  Si8        50        18        13      Si8          i 
18          384  5        42      S    8        20 


38 

30 

9 

20 

South  1  8 

50 

56 

00 

38 

40 

45 

30 

South  26 

00 

302  LOWE     OBSERVATORY. 

These  positions  are  for  the  centers  of  the  dark  areas.  A  very 
large  black  space  is  in  Scorpio,  above  the  bifurcation  of  the 
Milky  Way.  It  is  doubtful  if  any  of  these  places  are  absolutely 
black ;  they  seem  so  to  the  eye  through  contrast  probably.  There 
is  light  in  all  that  part  of  space  cut  out  by  the  universe.  How 
futile  it  is  to  attempt  to  make  drawings  or  cuts  of  the  shape  of 
the  cosmical  edifice.  Its  plan  is  still  unknown.  It  is  well  enough, 
perhaps,  to  make  specifications  of  the  Galaxy  and  adjacent  stars, 
yet  all  these  are  tentative  so  far.  The  foundation  lower  than 
the  Milky  Way — the  original  granite  of  stars  or  corpuscles — 
must  be  studied  and  graphed  for  a  century  to  give  an  idea  of  the 
plan  of  nature.  And  then,  after  all,  the  problem  may  appear  to 
be  beyond  the  reach  of  man.  At  all  events,  much  attention  should 
be  given  to  this  wondrous  and  original  cosmical  nebulosity. 
Nearly  all  the.  larger  nebulae  visible  here  are  complex— 
those  with  clear-cut  boundaries  in  small  telescopes,  show  fila- 
ments and  streamers  in  the  Lowe  instrument.  The  Andromeda 
nebula  displays  intricate  convolutions,  and  looks  like  those  shown 
in  recent  graphs' — having  the  supposed  appearance  of  a  rudimen- 
tary solar  system. 

The  trifid  nebula  presents  an  infinity  of  detail  not  seen  in  a 
six-inch  telescope,  likewise  the  Omega  nebula,  while  nearly 
the  entire  constellation  of  Orion  is  simply  enshrouded  in  nebu- 
lous sheen,  the  great  central  nebula  showing  a  wealth  of  out- 
lying wisps,  streamers  and  spray.  The  dark  opening  is  not  dark, 
for  faint  light  is  always  seen  here.  It  seems  dark  by  contrast 
only.  There  are  two  filaments  extending  across  the  opening  at 
nearly  right  angles  to  its  length.  It  is  remarkable  to  have  an 
ocean  horizon  on  the  south,  for  stars  rise,  cut  out  small  arcs  and 
set  in  the  waves,  all  within  a  few  minutes  in  the  distant  south, 
The  giant  sun  Canopus  thrusts  its  fiery  darts  through  the  mists  of 
the  sea,  and  then  vanishes  behind  the  walls  of  Catalina  Island.  In 
coming  here  from  Illinois,  Lat.  41  degrees,  13  minutes,  to  Lat. 


LOWE     OBSERVATORY.  303 

34  deg.  17  m.,  a  zone  of  stars,  7  degrees  wide,  was  lifted  up,  all 
new.  It  has  been  explored  with  interest.  Not  the  least  among 
its  glories  is  the  wondrous  Omega  Centaur i  cluster,  where  8,000 
fine  stars  are  piled  in  heaps  in  a  small  area.  It  is  impossible  for 
one  to  form  any  conception  of  the  splendors  of  the 
Milky  Way  without  seeing  it  in  the  great  glass,  and  then  it  is 
still  impossible.  The  Galactic  hosts  are  splashed  and  strewn  in 
spray,  in  spirals,  and  jare  tumbled  in  confusion  on  a  carpet  of 
jet  black  velvet;  or  cosmical  hail  of  pearls  and  diamonds  on  black- 
ened wastes  of  space,  or  piled  in  heaps,  raked  into  windrows  and 
rolled  into  banks  and  bulwarks,  all  flashing  and  blazing  with  su- 
pernal colors.  These,  together  with  clusters  and  nebulae,  con- 
spire to  form  a  scene  surpassing  all  that  mortal  eye  can  ever  hope 
to  behold.  And  beyond  all  is  the  primordial  base,  the  cosmic 
floor.  A  typical  area  of  the  stellar  pavement  is  between  the 
trifled  nebula  in  Sagitarius  and  nebula  No.  6523,  Dreyer's  N. 
G.  C.  The  masonry  is  complete,  with  no  more  room  for  starry 
sand. 

Accompanying  this  article  is  a  graph  of  a  portion  of  the  Milky 
Way  in  the  southern  constellation,  the  Centaur,  invisible  from 
these  latitudes.  The  ring  around  the  star  Beta  Centauri  is  a 
diffraction  ring  due  to  the  action  of  the  lenses  on  light  and  not 
actually  around  the  star.  The  minute  specks  on  the  graph  are 
all  suns  like  our  own,  and  the  spectroscope  shows  that  they  are 
all  composed  of  the  same  modes  of  matter  whence  our  sun  and 
earth  are  made.  One  of  the  chief  discoveries  of  all  ages  was 
the  fact  that  all  that  part  of  the  universe  within  range  of  the  most 
powerful  telespectrographs  is  made  of  the  same  matter — the  side- 
ral  structure  is  a  unit.  The  black  cavernous  opening  shown  to 
the  right  and  above  the  star  is  most  awe-inspiring,  and,  like  these 
seen  in  great  numbers  in  the  fine  telescope  in  this  observatory. 
The  object  glass  is  16  inches  in  diameter,  and  the  focal  length 
is  22  feet.  It  was  made  by  Alvan  Clark,  Sr.,  with  his  own  ven- 


L  0  W II     OBSERVATORY. 


One  of  the  richest  regions  in  the  Milky  Way  in  the  Constellation  Sagitarius,  from 
photograph  by   Barnard  at  the  Lick   Observatory,   June    19,    1892. 


LOWE    OBSERVATORY.  3o5 

erable  hands.  It  is  simply  perfect.  The  writer  had  the  good 
fortune  to  be  with  Mr.  Clark,  half  a  day,  in  his  famous  work- 
shop in  Cambridgeport,  Mass.,  when  he  was  making  the  flint 
lens,  and  every  particular  of  lens  making  was  explained  and 
shown  by  this  remarkable  man.  Little  did  the  writer  think  that 
he  would  ever  be  putting  it  to  active  use  on  the  summit  of  a 
mountain  in  that  fairy-land — California.  This  occurred  in  1879. 

MODERN  ASTRONOMY  AND  ASTROPHYSICS. 

The  new  astronomy  is  quite  unlike  the  old.  The  introduction 
of  the  spectroscope  changed  all,  and  then  came  the  sensitive  plate 
and  made  another  change.  The  early  astronomy  contented  itself 
with  rinding  every  mathematical  law  of  the  solar  system  and  of 
the  external  sidereal  structure;  of  finding  the  mass,  volume  and 
density  of  the  sun,  planets  and  satellites,  and  of  a  few  stars,  and 
continued  the  work  of  the  practical  astronomers,  in  the  compu- 
tation of  the  moon's  place,  for  time,  and  the  making  of  Ephem- 
eeides  for  use  in  observatories  and  by  sailors,  and  a  vast  amount 
of  valuable  and  necessary  work.  But  now  comes  the  astrophys- 
icist and  tells  what  the  stars  are  made  of;  writes  their  history 
through  the  eons  of  the  past,  and  forecasts  their  future.  The 
capital  discovery — stellar  evolution — was  made  by  the  science  of 
astrophysics.  All  stars  whatever  are  incandescent  suns.  They 
grow  from  primordial  nebulae  through  infancy,  youth,  middle 
life  to  old  age  and  death.  They  are  now  seen  in  every  direction 
in  space,  in  every  possible  phase  of  evolution.  Leaves  in  a  forest 
do  not  pass  so  many  and  varied  changes  as  do  the  glowing  suns. 
The  spectroscope  detects  every  condition,  reveals  relative  ages  of 
suns,  and  then,  that  marvelous  thing,  the  graphic  plate,  catches 
the  fleeting  changes,  and  records  them  for  use  for  future  astrono- 
mers. Nature  cannot  lift  a  hand  anywhere  in  space  within  the 
reach  of  modern  instruments  without  being  instantly  graphed. 
Her  most  secret  laboratories  and  labyrinths  are  being  explored 


jo6  LOWE    OBSERVATORY. 

hourly.  A  plate  is  exposed  every  hour  of  the  year  somewhere  on 
earth.  For  if  the  stars  are  setting  at  some  observatory  they  are 
rising  or  passing  the  meridian  at  others.  That  imperturbable  eye 
— the  bromide  plate — is  always  gazing  at  the  stars  or  sun.  Thus, 
for  1901,  graphs  were  secured  of  the  sun  on  361  days. 

Astonishing  discoveries  are  now  being  made,  and  the  great 
bundle  of  magazines,  monographs,  reports  of  observatories,  tech- 
nical papers,  treatises  and  circulars  by  the  dozen,  received  almost 
daily  present  a  most  impressive  display  of  the  present  intense 
activity  of  the  human  mind.  Since  history  began  there  has  not 
been  such  incessant  labor  wrought.  And  no  labor  ever  performed 
by  the  human  frame  is  more  arduous  and  exacting  than  that 
hourly  engaged  in  by  a  working  astrophysicist.  A  trained  astron- 
omer is  a  machine  of  precision,  with  every  phase  of  bodily  life? 
every  faculty  of  mind,  everything  in  his  being,  an  abject  slave 
to  indomitable  will.  And  that  will  is  immovably  set  and  bent  on 
finding  the  secrets  of  the  vast  cosmical  building  round  about. 

RESULTS. 

The  universe  is  now  known  to  be  a  growth.  Evolution  is  seen 
to  set  in  with  the  faintest  possible  rare  masses  of  gaseous  neb- 
ulae. They  condense  into  smaller  and  brighter  objects.  Con- 
densation continues  for  countless  ages,  and  each  becomes  a  sun. 
Heat  ever  escapes,  each  sun  passes  its  zenith  of  glory  and  dies. 
If  a  dead  sun  happens  to  be  drawn  into  an  orbit  around  a  living 
one,  the  body  so  drawn  in  becomes  a  planet,  and  may  become 
inhabited,  and  undoubtedly  will  if  water  appears.  Finally  both 
planet  and  sun  expire,  and  the  lifeless  planet  will  still  make  cir- 
cuit around  its  frigid  sun  and  count  off  useless  years — unless 
there  is  a  resisting  medium  in  space.  If  so,  the  revolving  world 
will  wind  down  a  spiral  and  ricochet  on  the  surface  of  the  central 
sun,  the  impacts  liberating  heat  again. 

The  only  hope  of  reanimation  of  dead  suns  and  ruined  worlds 


LOWE    OBSERVATORY.  307 

is  by  wholesale  collisions  where  these  bodies  by  the  billion  rush 
to  a  common  center  and  generate  heat  enough  to-  dissipate  all  back 
to  the  original  corpuscular  state  again.  Countless  suns  are  now 
seen  to  be  dying  from  loss  of  heat,  and  from  motion  seen  in  some 
notable  stars,  it  is  coming  to  be  realized  that  the  quantity  of  mat- 
ter now  stored  in  dead  worlds  is  greatly  in  excess  of  that  in  the 
living.  The  whole  sidereal  edifice  has  been  graphed  on  more 
than  25,000  plates,  in  pursuance  of  the  act  of  the  Congress  of 
Astronomers  in  Paris  in  1887.  Many  of  the  stellar  images  on 
these  have  been  counted  under  microscopes.  If  all  have  the  same 
average,  the  total  number  of  stars  appearing  will  fall  between 
100,000,000  and  125,000,000.  But  assign  to  each  of  these  any 
mass  within  bounds  of  reason,  then  by  the  laws  of  gravity  and 
motion,  it  can  be  shown  that  they  contain  only  a  minute  fraction 
of  the  entire  quantity  of  existing  matter.  Hence  dark  worlds 
are  immensely  more  numerous  than  those  that  are  active,  giving 
out  heat  and  light.  So  that  those  now  shining  are  mere  funeral 
tapers,  lighting  up  the  cheerless  and  melancholy  pathways  of  an- 
cient suns  and  forsaken  worlds.  That  part  of  nature  within 
reach  of  the  best  telescopes  is  of  inconceivable  antiquity  and  mag- 
nitude. The  first  and  amazing  fact  encountered  by  astronomers 
is  that  of  the  interminable  space  round  about.  For  the  nearest 
neighboring  sun  to  ours  is  25  million  million  miles  away,  and  oth- 
ers are  a  hundred,  yea,  a  thousand  times  more  distant.  In  the 
evolution  of  suns,  so  far  as  science  can  now  see,  heat  was  the 
first  to  appear  in  condensing  matter,  unless,  indeed,  electricity, 
or  "cold"  light  preceded  it.  Primordial  absolute  zero,  besides 
which  frozen  hydrogen  and  solid  blocks  of  air  appear  warm,  pre- 
ceded activity.  At  all  events,  light  succeeds  heat.  Moisture 
appeared  late  in  evolution.  Then  tardy  life  came  upon  cool 
worlds,  and  that  evanescent,  transitory  and  ephemeral,  ultimate 
and  final  refinement  of  matter — mind — was  the  last  to  appear  in 
the  midst  of  the  tremendous  cosmic  scene.  It  cannot  exist  long, 


308  LOWE     OBSERVATORY. 

for  such  worlds  as  the  earth  are  habitable  for  an  hour  or  a  day 
only,  compared  with  the  duration  ofa  structural  universe  of  mat- 
ter. So  mind  and  life  will  be  the  first  to  vanish.  Absolute  zero 
of  temperature  is  the  normal  condition  of  matter  and  space.  For 
when  primordial  matter  was  so  attenuated  that  a  volume  of  it  of 
the  size  of  the  earth  only  contained  enough  to  weigh  127  pounds,  it 
did  not  retain  heat.  So  heat,  light,  life  and  mind  appear  to  be 
mere  episodes  in  cosmic  fluctuations  and  surging  of  matter.  As- 
trophysics has  shown  the  earth's  place  in  nature.  The  dust,  of 
which  easily  1,000,000  particles  are  lying  on  the  page  of  the 
Overland  Monthly,  are  each  as  large  in  proportion  to  the  thick- 
ness and  area  of  the  magazine,  or  of  the  cubical  space  of  the  room 
in  which  the  reader  may  be,  as  is  the  earth  to  that  portion  of 
space  included  within  the  envelope  of  stars  at  the  extreme  limit 
of  vision  in  the  4O-inch  telescope.  These  stars  are  of  the  sev- 
enteenth magnitude,  and  from  photometric  observations  it  is  al- 
most certain  that  they  are  at  least  so  far  distant  that  light  trav- 
eling with  the  known  speed  of  186,000  miles  per  second,  requires 
15,000  years  to  come  hither.  This  makes  the  sphere  of  suns  vis- 
ible in  the  Lick  and  Yerkes  glasses,  30,000  light  years  in  diame- 
ter. The  particles  of  dust,  1,000,000  to  the  page,  are  too  large. 
So  now,  astrophysics  has  demonstrated  its  extreme  value,  for 
man  for  the  first  time  on  earth  knows  the  earth's  place  and  his 
own. 

THE  INCLINED  RAILWAY. 

Neither  Suphis,  the  monarch  builder  of  Egypt,  nor  Rameses 
II.,  did  a  greater  work  than  the  inclined  railway  up  Echo  Moun- 
tain. Engineers  and  railroad  contractors  from  all  parts  of  the 
world  pronounce  it  to  be  a  model  of  high-class  engineering.  Its 
length  is  3,000  feet  and  vertical  ascent  of  1,325  feet,  with  grades 
of  45,  48,  55  and  62  per  cent.  Two  white  chariots  balance  on 
one  endless  steel  wire  cable,  the  car  Rubio  being  down,  and  Echo 
invisible  at  the  top,  to  the  left  of  Hotel  Chalet  in  the  cut.  There 


LOWE     OBSERVATORY. 


309 


The  Inclined  Railway,  Echo  Mountain,  California.      Length,  3,1100  feet.      Vertical 

Ascent  1,325  feet  from  bottom  of  Rubio  Canyon,  to  the  top  of  Kcho 

Mountain.    Time  of  ascent  of  cars,  eight  minutes. 

are  three  rails  with  two  cars  which  pass  automatically  half  way 
up  at  the  switch,  which  is  shown.  The  great  motors  are  at  the 
top,  and  are  actuated  by  electricity,  brought  from  the  Santa  Ana 
river  90  miles  away.  The  current  comes  to  Pasadena  on  three 
wires  at  a  pressure  of  33,000  volts,  with  50  cycles.  Here  it  is 
stepped  to  2,200  volts  and  sent  to  the  power  house  on  Echo  Moun- 
tain, where  its  potential  is  again  lowered  to  the  usual  railway 
pressure,  and  made  direct  by  a  General  Electric  Company  20  am- 


3io  LOWE    OBSERVATORY. 

pere  induction  motor.  In  case  this  circuit  should  fail,  there  are 
dynamos  at  the  foot  of  the  incline  in  the  building  to  the  left, 
turned  by  two  Pelton  wheels,  run  by  water  from  a  reservoir  near 
the  observatory,  1,500  feet  above.  The  pressure  is  terrific,  and 
the  struggle  of  the  water  to  escape  its  narrow  prison,  the  half- 
inch  nozzle,  the  hissing  and  trembling  and  throbbing  of  the  pent- 
up  force,  are  impressive.  The  escaping  water  has  more  the  ap- 
pearance of  a  solid  rod  of  metal  than  a  thin  liquid,  and  would 
instantly  take  the  life  of  a  man  if  it  struck  squarely  over  the  lungs. 

The  white  chariots,  Echo  and  Rubio,  making  ascent  in  eight 
minutes,  lift  the  startled  tourist  from  the  gloom  lowering  in  the 
canyon  below  to  a  stupendous  transformation  scene  above.  If, 
as  often  happens  in  the  rainy  season,  clouds  extend  from  the 
depths  of  the  canyon  to  half  the  height  of  the  incline — then  lan- 
guage— spoken  or  written — or  brush  or  pencil  of  artist  are  im- 
potent to  portray  the  marvelous  change  that  awaits  the  traveler. 
Unrivaled  splendors  burst  upon  the  startled  eyes ;  and  not  the 
sumptuous  transformation  of  scene-painters,  nor  wand  of  ma- 
gician, nor  witchery  of  optical  illusion,  nor  spell  of  enchantress, 
can  equal  it. 

Under  the  great  tree  to  the  right,  at  the  foot  of  the  incline,  is 
the  mouth  of  Rubio  Canyon,  hewn  in  primeval  porphyritic  rock. 
It  is  a  rift  or  gorge  in  the  mountains  formed  on  that  auspicious 
day  when  good  Dame  Nature  lifted  up  old  Sierra  Madre's  range, 
through  the  bottom  of  an  ancient  sea.  It  extends  to  a  depth  of 
1,000  feet  under  the  hotel,  and  continues  in  sinuous  course  to  the 
observatory,  where  its  depth  is  670  feet.  This  canyon  is  wild, 
and  within  its  jaws  nature  at  first  frightens,  and  threatens  to  hurl 
chaotic  rocks  upon  the  explorer,  and  then  pleases,  dispels  fear 
and  woos  with  ferns,  flowers  and  trailing  vines — with  cool 
streams  and  miniature  whirlpools,  until  one  arrives  by  winding 
stairs  at  the  foot  of  Rubio  Falls,  100  feet  in  height.  The  peaks 
to  the  east  of  the  observatory  are  rightly  named  Echo  Mountains. 


LOWE    OBSERVATORY. 

They  repeat  all  that  is  spoken  to  them,  and  if  one  stands  in  the 
right  place  he  hears  seven  echoes.  The  colossal  walls  met  with 
a  surprise  last  spring.  The  great  singer,  Calve,  came  and  sang 
and  poured  forth  her  wealth  of  song.  The  startled  rocks  were 
taken  all  unawares,  and  at  first,  were  abashed.  For  nameless 
centuries  they  had  not  heard  sound  save  that  of  hoarse  notes  of 
raging  elemental  war.  Their  chagrin  and  discomfiture  remained 
for  a  moment  only,  when  they  relaxed  their  stony  throats,  and 
answering,  gave  back  all  the  marvelous  tones. 

The  great  circular  bridge  far  above  the  observatory  on  the  road 
to  Mount  Lowe  is  also  a  marvel  of  engineering.  The  view  from 
Lowe  Observatory  is  one  of  beauty  and  magnificence.  The  land 
area  visible  is  900  square  miles.  In  every  direction  the  land  is 
arranged  in  squares  and  parallelograms,  planted  to  oranges,  lem- 
ons, apricots,  olives,  prunes,  peaches,  figs,  nectarines,  almonds, 
grapes,  and  walnuts.  Kaleidoscopic  changes  of  color  succeed  in 
the  flowers  and  leaves  throughout  the  year.  The  green  is  per- 
petual. The  entire  valley  is  a  scene  of  intense  activity  from 
Christmas  to  May,  gathering,  packing  and  shipping  oranges  and 
lemons.  In  summer  the  apricot  harvest  is  a  sight  to  behold,  and 
in  autumn  it  is  difficult  to  secure  workers  to  gather  the  tons  of 
grapes.  The  writer  dare  not  attempt  to  describe  the  climate. 
One  must  live  here  to  form  any  conception  of  its  loveliness.  The 
extensive  ocean  front  is  being  transformed  into  a  continuous  sum- 
mer resort  for  miles,  as  fast  as  money  and  men  can  build  cottages, 
bath  houses,  wharves,  walks  and  everything  else,  like  Atlantic 
City,  Long  Branch,  and  all  other  Eastern  beaches.  Cloud  effects 
on  Mt.  Lowe  in  the  rainy  period  are  a  never  ending  source  of 
wonder.  Thus  one  may  be  reading  near  a  window  in  bright  sun- 
shine. Suddenly  the  printed  page  grows  dim,  a  cloud  has  con- 
densed in  space  round  the  building  and  against  the  window  pane. 
Sunsets  have  been  attempted  by  artists,  and  also  by  able  writers^ 
who  handle  words  as  one  would  sticks  and  stones,  but  both  find 


312 


LOWE    OBSHRVATORY. 


II 


u  o 

(U  tn 


N 


LOWE    OBSERVATORY. 

their  powers  begin  to  fail  and  wane.  When  the  entire  land  and 
sea  are  covered  with  clouds,  say  from  100  to  1000  feet  below  the 
observatory,  the  top  layer  is  simply  indescribable  in  its  supernal 
glory.  It  is  then  the  sun  is  supreme  in  its  inconceivable  majesty 
and  splendor,  for  the  earth  is  invisible.  And  again,  it  is  no  oc- 
casion for  surprise  that  our  own  great  ancestors — the  Aryans — 
worshiped  the  solar  globe. 

GREAT  ELECTRIC  STORM. 

A  most  appalling  electric  storm  raged  here  during  four 
hours  on  the  night  of  June  10,  1902.  No  rain  fell.  It  was  a 
remarkable  conflict  of  lightning  and  riven  peaks.  Terrific  flashes 
of  chain  lightning  burst  forth  from  inky  clouds  at  the  rate  of  two 
per  minute  during  the  four  eventful  hours.  The  thunders  of 
Gettysburg  and  Chicamauga  roared  and  crashed  round  the 
frightened  summits  and  bellowed  to  the  lowest  canyon's  depths. 
The  awful  turbulence  of  Mount  Pelee  was  repeated,  perhaps  as  far 
as  electricity  could  imitate  that  upheaval.  Lightning  was  seen' 
to  strike  peaks  many  times.  One  bolt  fell  close  to  the  observa- 
tory, and  one  struck  the  Chalet  Hotel.  The  vast  cloud  masses 
came  from  the  northeast.  After  bombarding  the  mountain  for 
three  hours,  the  entire  mass  moved  southwest  and  became  de- 
pressed perhaps  a  thousand  feet.  This  had  the  effect  of  mak- 
ing the  center  of  the  storm  appear  to  be  on  a  level  with  the  ob- 
servatory, with  the  astonishing  experience  of  beholding  the  top 
and  side  of  a  terrible  battle  of  electricity.  The  sinister  monster 
—the  widening  cloud — spread  over  Pasadena  and  Los  Angeles. 
The  explosions  of  electricity  were  almost  continuous  with  each 
streak  of  vertical  lightning.  It  seemed  that  both  cities  were 
doomed  to  certain  destruction.  This  display,  awful  in  its 
grandeur,  kept  up  for  one  hour,  then  moved  away,  and  hurled  its 
furious  rage  upon  the  sea  and  rushed  towards  that  bulwark,  the 


3*4- 


LOWE    OBSERVATORY. 


LOWE    OBSERVATORY. 

mountain  island  of  Catalina.     No  damage  was  sustained  by  either 
city,  while  a  slight  but  welcome  rain  fell. 

NOVEMBER  METEORS. 

The  literature  of  the  world  recounts  the  glories  of  the  shower 
of  meteors  as  seen  at  Niagara  Falls  on  November  13,  1833.  But 
whatever  splendors  were  beheld  there,  they  could  not  be  more 
magnificent  than  the  impressive  display  on  this  silent  and  soli- 
tary peak  from  midnight  to  dawn  on  November  15,  1901.  It 
was  a  fire  of  shot  and  shell,  from  one  to  five  per  minute — a  ce- 
lestial battle — entirely  without  sound.  This  intense  silence  made 
the  scene  one  of  the  utmost  sublimity,  and  the  effect  on  one's 
mind  cannot  be  conveyed  to  another.  Swords,  scimiters  and 
flashing  spears  were  thrust  against  a  hundred  lightning-scarred 
and  sand-sculptured  summits.  Vast  bombs,  aimed  at  peaks, 
burst  into  glittering  fragments,  only  to  be  succeeded  by  others, 
some  aimed,  so  it  seemed,  directly  at  the  white  dome  of  the  ob- 
servatory. Others  shot  with  terrific  speed  into  the  wilderness 
of  electric  lights  in  the  slumbering  city  below,  and  still  others 
hurled  themselves  into  the  sea,  or  sought  to  throw  down  the 
battlements  of  Santa  Monica  mountains  in  the  distant  west,  or 
disrupt  the  walls  of  Catalina  in  the  south.  Of  course,  these  ef- 
fects were  due  to  perspective,  not  one  being,  doubtless,  within 
fifty  miles  of  the  earth.  The  wondrous  apparition  was  on  dis- 
play until  the  advancing  splendors  of  the  sun  came  on  and  put 
out  the  light  of  all  lesser  glories.  During  this  memorable 
shower,  661  meteors  of  all  sizes  were  counted.  The  writer  was 
alone  in  the  majestic  solitude,  and  therefore  saw  at  the  most  only 
one-fourth  of  the  entire  fall.  Referring  again  to  the  impres- 
sive silence,  it  is  well  to  say  that  it  makes  powerful  impress  on 
the  mind.  At  the  midnight  hour,  the  stillness  is  so  profound, 
that  by  a  slight  excess  of  mental  imagery,  one  might  think  he 
heard  sound  issuing  forth  from  the  axis  of  the  earth  in  its  turn- 


3i6 


LOWE    OBSERVATORY. 


t 

o 


LOWE    OBSERVATORY.  317 

ing.  Nature  sets  up  opposition  everywhere  and  it  is  a  study  to 
see  the  rivalry  between  the  humming  birds  and  bees  for  honey 
on  the  mountain  slopes,  laden  with  their  burdens  of  flowers.  So, 
to  geologists,  biologists,  entomologists,  botanists,  mineralogists, 
microscopists,  metereologists,  naturalists,  lovers  of  nature  in  her 
most  splendid  forms  and  modes,  students  of  the  sea,  growers  of 
fruit,  engineers,  electricians,  railroad  builders,  mountain  climbers, 
explorers,  spectroscopists,  photographers,  artists  and  astrono- 
mers, it  is  said,  come  to  this  wondrous  place — Echo  Mountain. 
For: 

"To   him   who   in   the   love   of   nature   holds 
Communion  with  her  visible  forms, 
She  speaks  a  various  language." 

But  she  speaks  not  in  more  tongues  than  here;  strange  dia- 
lects of  nature — speech  seem  to  come  up  from  the  canyons,  and 
new  words  of  wisdom  from  the  mountain  walls.  Nature  teaches 
in  the  midnight  hour,  and  repeats  her  lesson  until  solar  glories 
appear  in  the  East.  Runic  writings,  Egyptian  glyphs  and  Cunei- 
form script  are  everywhere  impressed  on  plants,  in  the  canyon's 
abyss,  on  the  [mountain  sides,  in  the  vale  below,  and  amid  the 
labyrinths  of  space  between  the  stars  above.  And  had'  Bret 
Harte,  the  lover  of  nature  in  all  her  varying  moods,  whether 
lowly  or  magnificent — California  modes — which  he  made  his 
own ;  had  that  poet  of  nature,  who  sang  of  her  splendors  amid 
"the  pines  by  the  sea,"  or  "in  the  valley  below,"  or  beheld  some 
nature-glory  "across  the  distant  unfathomable  reach/'  stood  here 
at  sunset  point  on  the  canyon's  brink,  to>  see  a  day  die ;  had  Bret 
Harte  been  here  on  this  summit  in  fairyland  when  lightning 
flashed,  or  meteors  shot  across  the  midnight  sky,  or  had  he  lis- 
tened to  the  voices  of  nature  in  the  night,  issuing  forth  from 
gaping  canyons  or  granite  walls,  had  he  been  here,  he  would 
have  found  words  to  convey  impress  of  the  amazing  scenes  to 


3i8  LOWE    OBSERVATORY. 

other  and  waiting  minds.  For  did  he  not  bring  pre-histonc 
time  to  the  present  when  he  sang  of  a  cone  from  one  of  the 
gigantic  trees  of  Mariposa,  a 

"Brown   foundling  of  the  Western  wood, 
Babe  of  primeval  wilderness. 
Long  on  my  table  hast  thou  stood 
As  though  ten  centuries  were  not 
Imprisoned  in  thy  shining  case." 

And  this — rivaling  Burns — in  the  poem  "Hearts  Ease:" 

"By  scattered  rocks  and  turbid  waters  shifting, 

By  furrowed  glade  and  dell, 
To  feverish  men  thy  calm,  sweet  face  uplifting, 

Thou  stayest  them  to  tell 
The  delicate  thought  that  cannot  find  expression. 

For  ruder  speech  too  fair, 
That,  like  petals,  trembles  in  possession, 

And  scatters  in  the  air. 
The  miner  pauses  in  his  rugged  labor, 

And  leaning  on  his  spade, 
Laughingly  calls  unto  his  comrade-neighbor. 

To  see  thy  charms  displayed." 


LOWE    OBSERVATORY.  j/p 


LOWE  OBSERVATORY. 

The  telescope  and  other  instruments  were  brought  to  Echo 
Mountain,  California,  and  installed  in  the  Lowe  Observatory  in 
August,  1894.  They  were  taken  from  the  Warner  Observatory 
in  Rochester,  New  York.  Dr.  Swift  was  director  of  that  insti- 
tution from  its  foundation.  The  addition  of  electric  lights  to  the 
city  spoiled  the  definition  in  telescope  of  all  faint  objects  in  the 
sky.  Prof.  T.  S.  C.  Lowe  then  secured  both  instruments  and 
astronomer  for  Southern  California.  Here  the  air  is  pure  and 
definition  perfect.  Dr.  Swift  came  with  all  the  apparatus,  super- 
intended the  erection  of  the  observatory  and  the  mounting  of  the 
telescope  on  its  pier.  He  remained  director  of  the  Lowe  Observa- 
tory until  December  31,  1900.  Many  of  his  famous  discoveries 
of  nebulae  were  made  here.  During  his  long  and  elaborate  ex- 
ploration of  the  heavens,  he  discovered,  measured  their  positions, 
and  catalogued  1302  nebulae,  about  half  of  these  being  discovered 
at  the  Lowe  Observatory.  He  also  discovered  thirteen  comets, 
several  being  detected  from  this  mountain  top.  He  retired  laden 
with  honors  at  the  age  of  eighty-three  years. 

The  comprehensive  plan  of  establishing  a  well-equipped  as- 
tronomical observatory  on  the  summit  of  Echo  Mountain,  at  a 
high  altitude  and  under  the  cloudless  skies  of  far-famed  Southern 
California  in  an  atmosphere  where  clearness  of  vision  and  steadi- 
ness of  observation  could  be  depended  upon  to  furnish  their  aid 
in  furthering  the  advancement  of  human  knowledge,  is  entirely 
due  to  the  untiring  efforts  and  devotion  to  science  of  a  man 
whose  name  has  become  a  household  word — Professor  T.  S.  C. 
Lowe. 


PHOTOGRAPHS    OF    SOLAR    PROMINENCES. 

Taken  at  the  Yerkes  Observatory  by  Mr.  Ferdinand  Ellerman. 

Altitude  of  Prominence  in  lower  view,  185,000  miles 


LOWE    OBSERVATORY.  321 

Any  handbook  of  the  Lowe  Observatory,  or  publication 
involving  the  scientific  research  of  this  institution,  would 
not  be  complete  without  a  sketch  of  this  remarkable  man, 
who  at  the  age  of  seventy,  when  most  men  are  wont  to  retire 
from  the  normal  occupations  of  life,  has  been  found  planning  for 
Southern  California  an  institution  of  research  and  learning  of 
which  the  Astronomical  Observatory  of  Echo  Mountain  was  but 
to  be  the  initial  step.  It  is  to  be  hoped  in  the  interests  of  science 
and  in  the  interests  of  the  fair  name  of  Southern  California  that 
the  plans  of  this  institution  which  have  been  slowly  but  surely 
evolving  in  the  mind  of  this  great  man  may  during  his  lifetime 
be  carried  to  a  concrete  issue.  In  the  meantime  it  may  be  truly 
said  that  he  has  in  two  ways  left  an  indelible  impress  on  the  com- 
munity in  which  he  has  chosen  his  abode.  First,  through  his 
connection  with  and  the  construction  of  the  great  engineering 
achievement,  the  Mount  Lowe  railway,  and  second,  through  his 
carrying  to  a  successful  finish,  the  Astronomical  Observatory 
on  Echo  Mountain,  which  bears  his  name.  The  former  marks 
an  epoch  in  the  material  advancement  of  Southern  California; 
the  latter  points  with  pride  to  the  pari  passu  advancement  of  a 
love  for  science  in  our  section  of  the  country. 

Born  in  New  Hampshire  in  the  year  1832  from  old  New 
England  stock,  he  inherited  from  his  parents  all  the  sturdy  quali- 
fications for  which  the  descendants  of  the  pilgrims  have  become 
so  well  known. 

It  was  at  an  early  age  that  his  attention  was  turned  to  the 
sciences,  and  especially  to  the  subject  of  meteorology.  A  ques- 
tion confronted  him  involving  the  probability  of  the  existence  of 
permanent  air  currents  in  the  upper  strata  of  the  earth's  at- 
mosphere, air  currents  which  in  his  opinion  must  necessarily  exist 
and  be  moving  in  a  direction  parallel  to  the  earth's  rotation  on 
its  axis.  He  gave  much  of  his  time  and  talent  to  this  fascinating 
subject.  After  long  and  serious  deliberation  he  concluded  that 


322  LOWE    OBSERVATORY. 

the  only  method  of  solving  the  problem  was  to  ascend  in  a 
balloon  to  an  altitude  above  the  earth's  surface  sufficiently  high 
to  attain  the  specific  conditions. 

It  was  this  that  led  Professor  Lowe's  attention  to  aero- 
nautics, and  on  the  2Oth  of  April,  1861,  at  4  o'clock  in  the  morn- 
ing we  find  him  leaving  Cincinnati  in  a  balloon.  The  voyage 
was  a  remarkable  one,  it  being  not  only  the  longest,  but  also  the 
quickest  aeronautic  excursion  on  record.  At  noon  on  the  same 
day  he  left  Cincinnati  he  arrived  at  the  Atlantic  coast  in  the  lati- 
tude of  South  Carolina.  A  remarkable  voyage  of  1000  miles 
had  been  performed  in  eight  hours.  The  existence  of  the  upper 
air  currents  became  an  established  fact. 

The  attention  of  the  United  States  government  was  attracted 
by  this  remarkable  feat.  Professor  Lowe's  services  were  en- 
listed for  the  organization  of  an  army  balloon  corps.  Rapid 
progress  was  made  in  the  improvement  of  balloons  for  war  pur- 
poses. It  was  found  that  this  service  under  the  direction  of  Pro- 
fessor Lowe  became  an  invaluable  aid  in  observing  the  move- 
ments of  the  enemy  during  the  civil  war. 

At  some  time  during  the  sixties  he  turned  his  attention  to 
other  inventions  which  have  proven  to  be  of  great  value  to 
mankind.  The  first  patents  for  machinery  for  making  ice  arti- 
ficially and  for  refrigerating  in  general  were  awarded  to  him  in 
the  year  1867. 

Again,  the  discovery  of  the  process  and  method  of  making 
illuminating  gas  by  what  is  known  as  the  Lowe  Water  Gas  Sys- 
tem is  due  entirely  to  his  inventive  genius.  This  system  has 
been  perfected  and  is  in  use  in  nearly  every  large  city  in  the 
United  States. 

These  are  but  a  few  of  Professor  T.  S.  C.  Lowe's  contribu- 
tions to  the  intellectual  and  material  advancement  of  his  fellow- 
men.  In  times  to  come,  generations  hence,  mankind  will  continue 
to  benefit  by  the  results  of  his  scientific  activity. 


SPECTRA  OF  THE; 

SHOWING 


NEW    STAR    IN    PERSEUS, 
ITS    EVOLUTION. 


PROFESSOR   BARNARD'S    PHOTOGRAPH    OF   A    DENSE   REGION 
IN    THE    GAIVAXY, 


END  OF  THE  YERKES  40-iNCH  TELESCOPE, 
WIIJJAMS  BAY,  WISCONSIN. 

Property  of  the  University  of  Chicago. 


THE    GREAT    NEBULA    IN    ORION. 
Photograph  by  Professor  E,  E.  Barnard. 


PROFESSOR    E.  E.  BARNARD'S    PHOTOGRAPH    OF    A    RICH 
REGION    IN    THE     MILKY    WAY. 


e  Observatory  taken  on  a  dark  night  by  means  of  the  Electrical  Searchlight, 

distance,  1800  feet.    Exposure  3  minutes. 
(Cut  by  courtesy  of  the  Photographic  Times  Bulletin,  New  York.) 


The  I,owe  Telescope.    Diameter  of  Object  Glass,  16  inches;   Focal  length,  22  feet. 
Made  by  Alvan  Clark  &  Sons.  Cambridgeport,  Massachusetts. 


INDEX 


Page 

Aberration  of  Radiance 204 

Aberration   and   Parallax 205 

Absorption   Spectra    55 

Absorption    57 

Absorption  Lines  by  Experiment.  .53 
Absolute  Zero  of  Temperature.  ..  168 

Acceleration    270 

Acceleration  of  Chaotic  Moon.  . .  .267 

Activity 275 

Activity  derived  from  Gravity.  ..  .276 

Activity  and  Velocity   291 

Alphabet    of    Nature 37 

Aldebaran   215 

Alpha   Centauri    232-234 

Amoeba   Making   Segmentation.  .  .262 

Ancient    Sun,    The 173 

Antiquity   of  the   Universe 292 

Analysis  of  Radiance  by  Means  of 

its  Spectra  44 

Apioid,    Poincare's     261 

Apioid    Sun   Dividing 261 

Aryans,  The   284 

Arc,   Electric    46 

Arc    Light   Carbons 60 

Arcturus    215 

Arequipa,    Peru,    Observatory.  ..  .222 

Asiatic  Climates    158 

Astronomical   Spectroscopy    51 

Astrophysics    283-305 

Astronomers   Baffled    195 

Astronomers'    Early    Struggles.  .  .194 

Attraction  of  Electricity 286-287 

Auroral   Displays    143 

Auroras  and  Sun-Spots   136 

Aurora,   Bock's    141 

Aurora,  April  16,  1882 147 

Australian    Graph    228 

Axis  of  Earth  Turning 315 


Page 

Barnard,  Professor  E.  E 220-237 

Barnard's  Graphs  of  Milky  Way 

237-304 

Beta  Lyrae  252-253 

Beta  Aurigse,  Spectrum  of 248 

Bessel  206 

Bessel's  Parallax  207 

Bhagavad  Gita  284 

Bigelow's  Spherical  Magnetic  Field 

H5 

Binary  Suns  229 

Bridge,  Great  Circular  311 

Bridges  Across  Sun-Spots  ...117-120 

Bradley's  Parallaxes  201 

Bromide  Plates  306 

Building  a  Spectroscope 34 

Building  a  Spectrum  24 

Bunsen  Burner  46 

Burnham,  Professor  S.  W 236 

Byron's  Last  Man  274 

California   Climate    311 

Campbell,  Professor  W.  W.... 82-257 

Campbell,    Eclipse    Outfit 99 

Canopns    215-226 

Capella   257 

Carbon  Photosphere  of  the  Sun..ioi 

Carbon,   Mystery   of 101-102-105 

Carbons    35-60 

Carbons,    Searchlight    35~37 

Carbons,  Arclight   37 

Catalysis    173 

Catalytic  Activity    173 

Ceaseless  Records  of  Sun 115 

Centrifugal  Tendency   267 

Chemism    171-174 

Chemistry  of  the    Sun 65 

Cipher  Dispatch  from  the  Sun 34 


330 


INDEX 


Page 

Clark,  Alvan 305 

Climate,  California  311 

Climate,  Mesopotamian 158 

Cluster  in  Perseus   227 

Cloud  Effects   311-312 

Coherer    145 

Cold  Light    290 

Comparison    of    Lines 66 

Congress  of  Astronomers 307 

Contraction   of   Suns 293 

Conservation  of  Areas 290 

Corpuscular  State  of  Matter 171 

Corpuscles,  J.  J.  Thomson's 17 

Corpuscles,  Are  Probably  Electri- 
city  17 

Corpuscles,   Oscillations   of 29 

Crooke's   Vacuum   Tubes 138 

Curies,  Discovery  of  Radic  Activ- 
ity     18 

Darwin,  Professor  George  H.... 

259-265 

Darwin,  Professor  George  H., 

Portrait 268 

Dark   Room    20 

Day,  The  First 264 

Dead  Worlds   306 

Detection  of  Binary  Suns 246 

Diffraction  of  Radiance. .  .22-40-42-45 

Diffraction   Grating    39 

Dispersion   of  Radiance 22 

Discovery  of  Spectroscopic   Bina- 
ries   239 

Dispersion,   Wide   80 

Distance  of  Nearest  Star.  .213-224-225 

Doolittle,   Professor   168 

Double   Stars    236 

Doppler's   Effect    239 

Dry   Plates    87 

Draper,  Professor  J.  W 85 

Draper,  Dr.  Henry 92 

Drift  of  Pleiades    278 

Dynamics  of  the  Sun 161 

Dynamics   of  Liquids    167 

Earth's  Place  and  Man's 215-293 

Earth,  a  Particle  of  Dust 64 

Earth  Compared  to  Solar  Explo- 
sions   74-75-76-77-81 

Earth  and  Moon  Inevitable 272 


Page 

Earth  and  Moon  Separating 271 

Echoes,  Remarkable 311 

Echo  Mountain   310 

Eccentricity  of  Stellar  Orbits 246 

Eclipse,   Path  of  Solar 98 

Eclipse,  South  America  and  Africa, 

94 

Eclipse  Showing  Sun's  Corona. 89-96 

Eclipse  of  Sun 89,  95,  96-129 

Edison,   Thomas   A 159 

Effect  on  Earth  of  Jets  on  Sun.  ..123 

Effect  of  Tidal  Friction 265 

Effect,  Doppler's  239 

Electricity    184-284 

Electricity  and   Magnetism 184 

Electrical    Induction    in    Primeval 

Nebulae 286-7 

Electrical  Attraction  Causing  Ro- 
tation     289 

Electro-Magnetism 131 

Electro-Chemism    175 

Electricity,  Long  Distance  Trans- 
mission    309 

Electric  Storm  313 

Electric  Inclined  Railway 308 

Electric  Arc   46 

Electric  Spark   46 

Energy,  Late  Definition  of 17 

Energy,  Radiant   17 

Energy,    Transmission    of 18 

Energy,  Seems  to  be  Eternal 293 

Energy,  a  Property  of  Matter.  . .  .293 

Energy  of  Light  177 

Energy,  Total  of  Sun 170 

Entropy,  Running  Down  of  Heat.  169 

Engines,   Three   Mighty 65 

Evershed,   Flash   Spectra 104 

Evolution,    Its   Vast   Import.  .270-293 
Evolution  Stamped  on  Universe.  .293 

Evolution  Wrought  by  Tides 263 

Evolution  of  the  Sidereal  Universe 

306 

Evolution  Slow  222 

Evolution  of  the  Earth  and  Moon. 269 

Evolution  Now  in  Activity 275 

Evolution  of  Suns 280 

Extreme  Diffusion  of  Matter 171 

Exploration  of  the  Universe 64 

Exploration    of    Cosmical    Laby- 
rinths     65 


Explosions  on  the  Sun 

74-75-76-77-81-88 

Faculse    on    the    Sun 117-118 

Fall   from  an  Infinite  Distance.  .  .291 

Falling    Forever    291 

Falling  on  the  Sun,  Velocity  of..  164 

Filaments  in   Sun-Spots 117 

First  Day    264 

First  Month   269 

Fissures  in  Primeval  Cosmical  Bod- 
ies     267 

Fizeau  b6 

Fleming,  Mrs.,  Graphic  Measures. 226 
Flamstead,   Search   for  Parallax.  .199 

Flash    Spectrum,    The 100 

Foucault    86 

Fraunhofer's    Historic    Spectrum.  .33 

Fresnel's   Mirrors    40 

Fruits  and  Flowers 311 

Friction  Due  to  Tides 264 

Friction,   Effects   of 265 

Furrows,  on  Contracting  Masses. 267 

Future  of  Earth  and  Moon 272 

Future  of  the  Sun 274 

Galvanometer   185 

Galvanometer,  Mirror   186 

Gamma  Andromeda  230 

Gemmation,  Deep  Fact  in  Nature. 261 

Gemmation  of  Apioid  Suns 261 

Geisler   Tubes    140 

Glyphs,    Egyptian    317 

Grand    Panorama    311 

Gravity,  Seems  to  be  Eternal 276 

Gravity  and  Tides,  the  Builders.  .275 

Gravity  Potential  of  the  Sun 164 

Grating,    Diffraction    39-67 

Grating,  Ruled  14,438  Lines  to  Inch 

39 

Grating,  a  Mighty  Engine  for  Re- 
search    65 

Groombridge,  the  Star  1830 291 

Hale,   Professor  George  E 106 

Hale's  Spectroheliograph   107 

Hale's  Heliograph    112 

Hale's  Solar  Prominences  113 

Hale's   Snapshot  at  Solar  Promi- 
nence .  .  .112 


I N  D  E[X  331 

Page  Page 

Hale's   Composite  Graph    114 

Harmonics    25 

Harvard  College  Observatory. 214-222 
Harvard  Collection  of  Negatives. 226 
Harvard  Observatory  in  Peru.... 222 

Heat  Running  Down  179 

Heat  of  Sun,  Its  intensity 117 

Heat  Potential  of  Sun.  ..  .155-166-179 

Heat,  Sources  of  the  Sun's 162 

Heat  of  Impact  on  the  Sun 163 

Heat  and  Gravity 166 

Heat  Potential  of  Velocity 168 

Heat,  Light,  Life  and  Mind,  Ephe- 
meral   275 

,*Heat,  Its  Dissipation  in  Space....  168 

Heat  of  Stars  192 

Helium,  R.amsay's  Discovery  of.  ..283 
Heliostat  in  the  Lowe  Observatory 

197 

Herschel  Discovers  Binaries 229 

Helmholtz 172-178-179 

Henderson,  Work  on  Parallax.  .  .209 

Hertzian  Waves    85 

History  of  the  Sun 170 

History  of  the  Earth  and  Moon.  .271 

Hooke's    Stellar    Parallax 198 

Huggins'   Spectroscopy    87 

Hussey,   Professor   W.  J.,   Double 

Star  Work 236 

Hydrogen  17-280 

India,    Solar   Eclipse    in 99 

Induction,  Electrical,  Fundamental 

286-7 

Induced  Electricity  Causing  Rota- 
tion     289 

Interference  of  Radiance 40 

Interference  or  Diffraction  Spectra. 41 

Interminable  Space 212-307 

Infinite    Space,    Velocity    of    Fall 

from    291 

Infinity,  No  Impress  on  Mind.... 291 


Jets  on   Sun    81-123 

Joule's  Heat  Equivalent 163 

Keeler's    Spiral    Nebulae 285 

Kelvin,    the    Physicist 281 

Kepler's  Third  Law 232-252 

Kepler's  Spectrum   32 


INDEX 


Page 

Kinetic  Theory  of  Matter 163 

Kinetic  Energy,  Law  of 163 

Kirchhoff    22 

Kirchhoff's    Law 23-27-56 

Kirchhoff 's    Original    Work.. 54 

Langley,  Professor  S.   P 149 

Langley's  Account  of  Aurora.  ...  149 
Langley,  Measurement  of  the  Sun's 

Energy  157 

Langley,  Measurement  of  the  Sun's 

Heat 117-181 

Langley,    Spectro-Bolometer.  .182-187 

Langley,   New   Spectrum    189 

Langley,  Holograph    196'- 

Langley,  Energy  Spectrum   191 

Langley,  Bolometric  Spectrum.  . .  .182 
Langley,  Drawing  of  Sun-Spot.  ..  122 

Lantern,   Electric    49 

Lane's  Law  180 

Law,  Kirchhoff's  First   23 

Law,  Kirchhoff's  Second 27 

Law,  Kirchhoff's  Third 56 

Law,  Lane's   180 

Law  of  Kinetic  Energy 163 

Law,  Mathematical  and  Physical.  .260 

Law,   Kepler's  Third 232-252 

Law,  Stefan's  180 

Law  of  Velocity 163 

Law  of  Conservation  of  Areas.  . .  .290 

Law  of  Variation  of  Light 153 

Lick  Observatory  Eclipse  Expedi- 
tion     100 

Ligament,  between  Earth  and  Moon 

272 

Light   Waves    20 

Life  a  Late   Product  of  Matter.  .307 

Life  a  Mere  Episode 274 

Life  Ephemeral   274 

Lockyer's  Apparatus  61-63 

Lowe  Observatory    296 

Lowe,  Professor  T.  S.  C 307 

Magnetism  and  Sun-Spots 150 

Magnetic    Field    125-133 

Magnetic  Induction   131 

Magnetic    Storm    125-134 

Magnet,  The  Sun  a  Spherical.  144-145 

Matter,  Kinetic  Theory  of 163 

Matter,  Wide  Diffusion  of 171 


Page 

Matter,  Phases  of 36 

Matter,  Phases  of,  in  the  Sun 68 

Matter  Stored  in  Dead  Worlds.. 307 

Matter,  Quantity  of 291-292 

Matter  Seems  to  be  Eternal 276 

Matter,  Primordial  State  of 171 

Matter,  Corpuscular Jji 

Mars,  Moons  of  273 

Mass  of  the  Universe  292 

Mass  of  Binary  Suns 232-251 

Mass  of  the  Sun 292 

Mass  of  a  Corpuscle 18-280 

Maury,  Miss,  Measurement  of 

Graphs  226 

Men,  Pale  and  Faint 285 

Meridian  Photometer  153 

Meteoric  Shower  315 

Meyer's  Concept  of  Beta  Lyrae...253 

Mechanics  of  Tides  266 

Micrometer  195-196 

Micrometer,  Field  198 

Micrometer,  Screw  183 

Mind,  Last  Refinement  of  Matter. 293 

Mind,  Ephemeral  307 

Mills'  Spectrograph 241-242-245 

Modes  of  Matter  in  the  Sun 68 

Molyneux  201 

Motor,  the  Solar  159 

Motion  of  Stars  in  the  Line  of 

Sight  244 

Motion,  Proper,  of  Stars 277-8 

Motion  of  Pleiades  278 

Nearest   Neighboring   Sun.  ..  .195-224 

Nebulae   279-280-281 

Nebulae,  Spiral  285 

Nebulae  and  Suns  in  Evolution.  .  .282 

Negative   Ions    18 

Negatives  at  Harvard 226 

Nerve,   Platinum   26 

Newcomb,   Professor   Simon.  .219-257 

Newton's   Spectrum    32 

November  Meteors  315 

Nova  Persei    285 

Number  of  the  Lucid  Stars 214 

Observatory,  the  Lowe 296 

Observatory,  the  Lick 100 

Observatory,  Harvard  College 122 

Observatory,  Yerkes    215 


Page 

One  Hundred  Million  Suns 

219-222-292 

Orbits  of  Binary  Suns 246 

Outlines  of  Spectroscope   45 

Outfit,  Lick  Eclipse 99 

Palace  of  the  Universe 223 

Panorama,  Grand   311 

Parallax  of   Stars 194-200 

Parallax  of  Alpha  Centauri 209 

Parallax,  Bessel's  Method 207 

Parallax,  Cassini's  Attempt  to  Find 
2OO 

Path   of   Solar   Eclipse 98 

Path  of  the  Sun  in  Space 282 

Pelton    Water    Wheel 310 

Perseus,  New  Sun  in 285 

Phases  of  Matter  in  the  Sun 68 

Photography,    Astronomical    222 

Photography,  a  Majestic  Science.  .222 
Photography  of  All  the  Stars. 216-307 

Photography  of  the  Sun 85-88 

Photography  of  Eclipses 99 

Photography  of  the  Spectrum 71 

Photography  Stores  Knowledge  for 

the  Future  293 

Photography  of  Milky  Way.  .220-237 

Photography  of  Nebulae   285 

Photosphere  of  the  Sun,  the  Car- 
bon     101 

Photometer,  Meridian   153 

Plan  of  Palace  of  the  Universe.  .223 

Platinum   Nerve    26 

Plastic  Suns  Passing  in  Space... 260 
Plumbline  Sunk  in  Space.  .......  .260 

Plutarch  Mentions  Sun's   Corona.. 93 

Poincare's    Apioid    261 

Polaris    257 

Polarity    175 

Potential  of  the  Sun 151 

Potential    of    Velocity 161-164 

Potential  of  the  Universe 291 

Primordial  Electrical  Induction... 

286-7 

Primordial   Cosmical   Mass 281 

Primordial   State  of  Matter 171 

Primordial    Tides     263 

Prism     39 

Prismatic    Telespectroscope. . .  .80-256 
Prominences  on  the  Sun. .       .  .81-88 


INDEX  333 

Page 

Prominences  Hydrogenous    88 

Prominences     Seen     Without     an 

Eclipse   91 

Proper  Motion  of  the  Stars 277 

Profound  Solitude   315 

Pyroheliometer    156 

Pyramid    of    Sulphis 308 


Quantity  of  Heat  of  Sun 178 

Quantity   of   Matter 291-292 

Quadrillions  of  Dead  Worlds. ..  .292 
Quadrillions  of  Miles 281 

Radian,  A   210 

Radiant    Energy   Defined 17 

Radiant  Energy  and  its  Fixation.  .84 

Radiant  Sun,  the 117 

Radio-Activity   18 

Radium    18 

Railway,  the  Inclined 308 

Ramsay,    Approach     to    Absolute 

Zero    109 

Ramsay,  Discovery  of  Helium. 95-283 
Rarity  of  Primordial  Matter.  .171-308 
Records,  Ceaseless  Photographic.  .115 

Reservoir   at   Observatory 310 

Reversal   of   Spectrum   Lines 67 

Roemer,  Velocity  of  Light 202 

Roentgen  Waves  85 

Rotation,  Caused  by  Electrical  In- 
duction     286-7 

Rubio   Canyon    310 

Russel,  H.  N 257 

Scale   Applied   to    Spectra 58 

Searchlight    on    Echo     Mountain, 

3,000,000  Candle  Power 37 

Secchi    ..82 

See,  Dr.  J.  J.  T 168-172-259 

Sidereal  Structure,  the 212 

Sidereal   Sheets    299 

Silence    Profound    on    the    Moun- 
tains     315 

Sirius  215-254-253 

Slit  of   Spectroscope 31 

Slit  for  Solar  Work 72 

Smith,  Misses  Jennie  M.  and  Ma- 
tilda H 30 


334 


INDEX 


Page 

Solar  Activity   84 

Solar  Brightness  154 

Solar,    Constant,    the 157 

Solar   Dynamics    161 

Solar  Eclipse,   Path  of 98 

Solar  Eclipse  Outfit,  Campbell's.  .  .99 
Solar  Eclipse,  Thwaite's  Graph  of 

; 105 

Solar   Gravity   Potential 167 

Solar  Heat,   Sources  of 162 

Solar    Heat    Potential 166 

Solar  Jets    81 

Solar   Light    154 

Solar  Motor   159 

Solar  Origin  293 

Solar  Photograph,  Janssen's 92 

Solar  Prominences 74-5-6-7-81-88 

Solar  Prominences,   Hale's    113 

Solar    Spectroscopy    91 

Solar  Spectroscope   70-71 

Solar  Spectrum   22 

Solar    Spots..  .116-118-120-122-126-127 

Solar  Spots,  Langley's 122 

Solar  Spots  and  Auroras   136 

Solar  Chemistry    65 

Solar  Corona   89 

Solar   Potential    151 

Solitude  on  the  Mountains 315 

Space,  the  Standing  Mystery 283 

Spectrum  Analysis   23 

Spectroscope,    The    29-30-48 

Spectrograph,  the  Lowe 71 

Spectro-Bolometer    182 

Spectro-Chemistry    52 

Spectrum,  the  Flash 100-104 

Stars,    the    192 

Stellar   Evolution    258 

Stellar    Parallax    200 

Stellar  Universe    221 

Stellar    Motions    277 

Storm,  Great  Electric 313 

Sun's  Duration  of  Activity 179 

Suns   Flying  at   Random 259-277 

Summary    293 


Page 

Telespectroscope,  the  Lowe 71 

Terminal    Velocities    172 

Terrestrial  Influence  of  Sunspots.i3o 

The  Ancient  Sun 173 

The   Aryans    284 

Thomson,   Professor  J.  J.  .17-108-280 

Tides    265 

Tidal  Evolution 265 

Tides  Made  the  Earth  and  Moon265 

Universe,    Exploration    of 64 

Universe,  30,000  Light  Year  Diam- 
eter   , 281-291 

Universe,  a  Growth 306 

Universe,  Renewal  of 307 

Useless   Years    274 

Vacuum  Tubes 138-140 

Velocity,  Potential,  of  Sun.  ..  161-164 
Velocity,  Potential,  of  Universe.  .291 

Vista,    the    Grand 311 

Voices  of  the  Night 317 

Vogel's    Graphic   Telescope 2^/1 

Vogel's    Spectrograph    256 

Waves,  Types  of 19 

Wave  Motions  19 

Wave  Lengths  24 

Waves,  Hertzian  85 

Waves,  Roentgen  85 

Wave,  One  294 

Wave  Fronts,  Leaving  Grating... 39 

Wilcox,  Ella  Wheeler 200 

Willard  Lenses  220 

Waste  Products  of  the  Universe.  .275 
Whirlpools  in  Primordial  Nebulae 

290 

Worlds  Clutched  by  Tides 273 

Worlds  in  Final  Collision  294 

Worlds,  Dead,  More  Than  Living 

292-306 

Young,  Professor  Charles  A 

68-87-103-109-125-128-155 

Young,  Anna  Sewell 179 


ERRATA. 

Cuts  42,  page  105,  are  misplaced.     Upper  should  be  lower. 

Cut  46,  page  112,  is  bottom  up. 

Cut  60,  page  140,  Crooke's  Tubes,  should  read:  "Geisler's. 


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